Mobile rig for the price of a (Chinese) HT

So cheap you just have to buy one! According to the the listing it's VHF or UHF not dual band. Thanks to Steve G1KQH for the tip-off.

DXMaps needs your support!

The DXMaps website run by Gabriel EA6VQ needs your support. This is the site that plots contacts spotted to the DX Cluster on a map, band by band, to show propagation in real-time. It is especially invaluable during the summer Sporadic-E season to track the rapidly-moving band openings.

DXMaps plots DX contacts band by band in real time

The trouble with any web site is that if it becomes very popular the costs of running it grow beyond what most people can afford as a hobby. According to EA6VQ the cost of a new dedicated server for the site will be $250 a month. So he is asking users to become "supporter users" by donating $33 US per year. But any donation is welcome.

If you are an active operator, especially on six metres and up, you will know how invaluable DXMaps.com is. Hopefully hams will step up to the plate and send Gabriel a donation.

Nagoya holograms rumbled!

I've written on the subject of fake HT antennas on eBay before. It's a matter of concern whether an antenna is fake or genuine. Lately the antennas sold under the Nagoya brand name have come under suspicion. Recently purchased antennas have blue lettering printed directly on to the base, similar to some fake antennas purporting to be made by the reputable Diamond Antenna company.

Two identical fake hologram labels

These new Nagoyas come in an orange plastic sleeve rather than a yellow one. The sleeves carry a silver hologram label with two serial numbers on them. Presumably the idea is that if you want to check an antenna is genuine you can contact the manufacturer, give them the numbers and they will confirm or deny that the product is genuine.

Today I read in a Yahoo group that someone had obtained an antenna with an identical hologram sticker to another member. I have two such antennas but I had never thought to check the stickers. When I did, I found that the stickers that came with two different Nagoya antennas were identical!

You probably can't read the numbers off the picture above (try clicking the picture to see the full-size version) but the top number is TWx00647488x where x is a Chinese character. The lower number is CNx3333081x. If you have recently purchased Nagoya antennas and got ones with the silver sticker, I bet they have the same serial numbers!

It seems that the only way to be sure of getting an HT antenna that works is to buy a Diamond branded antenna from your reputable US, UK or EU dealer! Better still, take an antenna analyzer with you and test it before handing over any money.

Look, No IP

A couple of years ago we changed our broadband Internet service provider. The new provider did not support a static IP address. I have a QNAP network attached storage device which is primarily used for backup. However, it's actually a Linux box that runs the LAMP (Linux, Apache, MySQL and PHP) software which I occasionally use as a web server for experimentation. I sometimes need it to be accessible from the internet. So I opened a free account with DynDNS in order to access the server using a host name.

Some time last year after I came out of hospital I started to receive emails from DynDNS informing me that my account was being disabled due to abuse and inviting me to open a paid account. As far as I could tell, the only "abuse" was that my script to inform DynDNS of my current IP address was running more than the number of times DynDNS permitted. I had no idea why it should start misbehaving like that and cynically thought it was just a ploy to convert free users to paid subscriptions. I was in no frame of mind to deal with the problem, nor to dig into my wallet, so I simply closed the account and had done with it. This would have had the effect of breaking some APRS-related functions on my site but I had other things of greater concern to think about.

A few days ago I decided to look into why the CDGVHF ANSRVR group was not sending any messages. ANSRVR is an APRS tool used to send APRS messages to groups of interested people. CDGVHF stands for Cumbria Dumfries and Galloway VHF group and it is intended to disseminate alerts about VHF and UHF openings in the Cumbria, Dumfries and Galloway area (grid square IO84.) It's essentially a filter that acts on emails sent out by DX Sherlock and converts them to APRS messages addressed to ANSRVR. I could, of course, just have the emails sent to my smartphone. But it's more fun to make use of ham radio!

I looked for an alternative free service to DynDNS and decided to try No-IP Free. As far as I can tell, No-IP won't accuse you of abuse for updating your IP address too frequently, in fact its client software appears to do this every few minutes which seems like plenty. It does have a requirement that you confirm your account is being used once a month, which could be a bit annoying, but I'll see what happens at the next update.

In the meantime, CDGVHF is now sending out propagation alerts again. To receive alerts of VHF and UHF openings in the IO84 area just send an APRS message to ANSRVR with the text CQ CDGVHF. You'll need to repeat this from time to time as the server unsubscribes you from the group after 8 hours of no activity, unless you are using KJ4ERJ's APRSISCE software which can maintain your subscription for you.

New toys

There is nothing like some new toys to cheer you up when things get a bit boring! The G4ILO shack received two new arrivals this morning. Actually there was a third, non-radio addition that came yesterday as well, but that will have to wait for another posting.

The arrivals are two new handies - one a Baofeng UV-3R+ VHF/UHF dual band transceiver (note the plus,) the other a Wouxun KG699E low band VHF transceiver for 4 metres. My original UV-3R has found a new home, whilst the Taiwanese "professional" radio I got for 4 metres is just a rubbish radio.

I haven't had time to get to know the new radios. The Wouxun in particular is not intuitive and will require some intensive study of the manual. The Baofeng is functionally identical to the UV-3R Mark II but the build quality is much superior - on a par with the Wouxun and favourably comparable to the ham radio brands like Yaesu.

A major plus of the UV-3R+ is that you now get a professional grade drop-in charger. Besides a more rugged-feeling case it also has a metal belt clip - a big improvement over the flimsy plastic one that came with the earlier model. I believe that both radios use Kenwood specification accessories. This will be useful, if true, as I have two Kenwood radios as well. One of the first things I will have to do is find a wiring diagram for the programming cable because the one I made for the UV-3R Mk I has a 3.5mm 4-pole plug and is no longer useful.

Opera on 6

I haven't used the Opera digital mode on HF for a bit as it seemed that interest had dropped off and there is not much point in beaconing in no-one is receiving. It seems to be one of those modes where there is a resurgence of interest whenever there is something new to try. This weekend the new thing was some fast Opera modes for use on VHF so I fired up the K3 on 6m (50.700MHz) to see if I could receive anything.

As you can see, not only did I receive some other stations but my own Opera signals were received around the UK. No great DX, but I was only using 20W to my attic dipole and would not expect to hear anything on 6m at this time.

If enough people were prepared to use it, this could be a good tool for discovering Sporadic-E openings on the VHF bands. The 30 second transmit cycle seems more appropriate for this type of propagation than WSPR's two minute periods.

Four metres

There are a number of things I'd like to do radio-wise this year. One of them is to get equipped for SSB on four metres.

I have spent quite a lot over the last two or three years on 2m SSB and have very few contacts to show for it. My QTH in the Cockermouth Black Hole seems to be prevented by the Lake District mountains from receiving good signals from other English stations by normal propagation. I don't even experience much in the way of tropo openings here. The only real 2m DX I have worked are a handful of Sporadic-E (Es) contacts into Spain and Portugal. One thing I have learned is that 144MHz Es, which is a pretty rare thing in any case, is considerably rarer the further north you get. I was ill and recovering from my brain operation during the peak of the Es season last year but as far as I can tell from DX Sherlock no Sporadic-E openings on 2m reached this far north during 2011 so I didn't actually miss anything.

Six metres is another matter. I have made lots of contacts on the Magic Band even though my 6m antenna is just the addition of two quarter-wave wire elements to my multi-band attic dipole. Four metres won't be open as often as Six but it should sustain Sporadic-E propagation a lot more often than Two does. And now that many European countries have granted their amateurs 4m allocations I think there could be a good chance of working some summertime DX.

The plan depends on my finding space in my attic antenna farm for a 4m antenna. One of the first home improvements Olga and I will make this year is to replace the central heating boiler and we're advised that the most efficient types available now heat the water on demand and don't need a header tank or pipes in the loft. I'm a bit apprehensive about letting workmen loose in the attic when I'm not sure whether I'm capable of moving around safely up there to check my antennas are OK and repair any damage. But getting rid of the tank and copper pipes will make a bit more space for the antennas and hopefully allow me to mount a 4m Moxon on the rotator where the 2m one currently is.

I will also need a radio for 4m SSB. I guess I'm looking at getting a Spectrum Communications transverter for this. Probably a ready built one as I'm not really sure I can manage to assemble that complex a kit any more. I wonder if anyone has successfully modified an Elecraft XV50 for 70MHz?

DV Wars in 2012?

In 2012 Yaesu will introduce a range of digital voice radios to the amateur market. They have published a Digital Communications Guide for Amateur Radio Operators that describes their new system and answers some questions about it. Yaesu's offering seems to be compatible with Motorola's professional  digital mobile radio system, which offers hams the possibility of a second source of compatible equipment on the surplus market - not that used professional Motorola radios have ever been cheap. But the Yaesu system will not be compatible with D-Star. No surprise there, then.

I have always believed it was a foolish move for ham radio organizations like our RSGB to allow themselves to be bamboozled by Icom into permitting the creation of a digital network that gave one supplier a monopoly. Repeater groups and their members who have made substantial investments in D-Star technology are not going to want to switch to a different digital mode that makes existing hardware obsolete. On the other hand, D-Star itself is becoming an outmoded technology in digital terms. Hams who have been sitting on the fence looking for an up to date alternative that doesn't involve buying Icom are not going to plump for one system or the other while the future looks like being fragmented into rival factions. It will be like the video war between VHS and Betamax.

I think Yaesu's announcement will kill the already lame duck of D-Star and ensure that analogue FM remains the dominant mode on the amateur VHF bands and up for years to come.

Two new 2m repeater channels

According to the UK repeaters website, two new 2m repeater channels have been internationally agreed:

• 144.9750MHz input / 145.5750MHz output (RV46)
• 144.9875MHz input / 145.5875MHz output (RV47)

Though these channels are not available for use in the UK yet, the wording of the announcement suggests that they eventually will be.

Looks like we dinosaurs who still insist on calling the calling channel S20 are going to have to give up QSYing to S23!

Home-build D-Star radio

Years ago, after I built my Elecraft K2 I had the idea that I would only use home-built radio equipment. However I found that it was no longer possible to buy a kit to build a 2m FM radio. This afternoon I visited a site mentioned by Tim, G4VXE in his latest blog posting and was intrigued to find that a Dutch group is working on a design for a VHF/UHF transceiver kit. Not only that, it is apparently being developed in consultation with Elecraft and is built into an Elecraft EC-1 (K2) enclosure!

The basic kit will be for an analogue FM transceiver with modules for 2m, 70cm and 23cm (it isn't clear to me whether you must choose one of these bands or whether you can fit all of the modules.) But with the addition of another module it can also become a D-Star transceiver!

Now I have never made any secret of my dislike of D-Star, mainly due to the fact that one manufacturer has a monopoly on the provision of radios. But a home-brew D-Star transceiver that doesn't require you to buy anything from Icom and would sit neatly alongside my K2 in a matching enclosure could just be the thing that makes me swallow my objections. Yes, it will still have an AMBE chip containing the proprietary codec. But most of my radios contain chips with proprietary firmware so I don't think that's a good enough reason for continuing to avoid D-Star.

Baofeng in my shirt pocket

Only a few days after I had ordered the little Jin Ma Tong JMT-227 145MHz transceiver from China, news began to appear of a new miniature Chinese transceiver from Vero Telecom called the UV-3R which was a dual band (136-174 and 400-470MHz) transceiver. Eventually these began to appear from eBay sellers under the Chinese brand name Baofeng. The price was an astonishing £25 plus postage from Hong Kong. I ordered one from the seller hk360radio and it arrived in just over a week.

The Baofeng UV-3R comes in a colourfully printed box. Together with the radio the box contains the battery (Li-ion 3.7V 1500mAH), a charger with two-pin socket and adapter for UK mains sockets, two antennas (one for VHF and one for UHF), an earpiece/microphone similar to a mobile phone hands-free kit and a manual written completely in mostly pretty good English. There is also a blue carrying strap carrying the seller's name which is so cheap and nasty it is unlikely anyone would use it.

Not mentioned in the manual's list of included accessories but also supplied was a cradle that can hold the radio while charging the battery externally. Why you should wish to do this when you can charge the battery installed in the radio I have no idea. There are no charging contacts on the radio, you have to charge it by inserting the small barrel connector into the socket in the side or by taking the battery out. There is also a short cable with one of these barrel connectors on each end, the purpose of which no-one figured out yet.

The UV-3R makes the JMT-227 look a quality product. This is the first new electronic product I've had that didn't come with a peel-off protective film over the display. The plastic casing is extremely thin and the plastic belt clip that can optionally be attached looks as if it would easily break. To be fair, the flimsiness of the Baofeng may not be due to cheapness but to save weight. The radio is extremely small and very light, just 125 grams (5 oz) with battery inserted and antenna attached.

The provision of two separate antennas for VHF and UHF may be a cost saving measure or it may be for efficiency reasons (a single band antenna is usually more efficient.) However it is not convenient for a user who wishes to make regular use of both bands. The antenna connector is an SMA female, as used by all the Japanese ham radio manufacturers. Frequent changing of the antenna will result in wear of the connector and ultimately a poor contact as the centre pin of the antenna rotates in the socket. Some eBay sellers are now supplying this radio with a single, dual-band antenna. This is something to look out for when buying.

I had originally intended fitting an SMA to BNC adapter to the Baofeng as I have with all my other handheld radios but the UV-3R is so small and light that it seems inappropriate. I doubt that the radio is ruggedly enough constructed to take the stress of using one of the larger BNC antennas in any case.

Confusingly, the rotary switch on top of the radio must be pulled up before it can be rotated. Once you have realized that, the UV-3R is easy to use and easy to program the simplex channels and local repeaters into the memories by hand. There is free programming software available on the web. Programming cables are becoming available to buy on eBay but it isn't necessary to use the software, unlike with early models of the UV-3R which had very limited menus that did not allow the changing of things like step size or power level except through the programming software. (This is something to bear in mind if considering buying a used one.)

But this radio is evolving rapidly. The manual that came with mine describes 12 different menu settings but the radio actually has 18. Every setting you would want to change can now be set through the keypad. The settings are also stored in the memories - even the selected power level, so that I can have the radio use low power whenever I use it to communicate with my Echolink node. Perfect!

The one thing it does not seem to be possible to do without the software is to program cross-band splits, such as listen on UHF and transmit on VHF. This could be useful for working FM satellites. But I am not very bothered about this.

All the usual RX and TX tones are supported for repeater access. A 1750Hz tone burst is generated by pressing PTT + VOL. The radio also receives Band 2 FM. The quality is not very good, but on the plus side FM reception is interrupted if a signal is received on the currently selected amateur frequency.

The performance of the little radio seemed to be well within spec. On a fully charged battery the output power on 2m was 2.6W while on low power it was 320mW. (At 433.50MHz the respective measurements were 2.4W and 1.2W.)

The sensitivity is also excellent. The box and some advertisements claim the UV-3R uses DSP. As no schematic is available I have no idea. All I can say is that the received audio is very clear and pleasant and that the signal to noise ratio receiving a distant repeater on the UV-3R with its short VHF antenna was better than on the Kenwood TH-D72 with its dual band antenna standing in the same place.

Newer versions of the UV-3R including this one now have an S-meter on receive, though it works in coarse steps. I also checked the strong signal handling performance of the receiver the same way I did recently with my other hand-held transceivers. It was on a par with the VX-8GR and the JMT-227, at the poor end of the spectrum.

The transmitted audio is very good, if slightly lower in level than some of the ham rigs. One local said my audio sounded "just like my normal audio." The LED on the front of  the radio is supposed to glow red on transmit and green when a signal is received. Mine does not glow red, although the S-meter goes full scale to indicate power out. This appears to be a fault, but not one worth sending the radio back to Hong Kong to fix. However, this perhaps tells us something about the level of quality control you can expect for this price.

I have recorded an audio sample off-air, together with one of the Kenwood TH-D72 for comparison:

• Baofeng UV-3R using built-in microphone
• Kenwood TH-D72 using built-in microphone

The earpiece/hands-free mic supplied with the radio is not useful. I had some trouble with the audio but the main problem is that after you press PTT the radio locks in transmit. This appears to be due to RF feedback into the earpiece/mic cable as it doesn't happen on the low power setting.

Using the supplied VHF antenna I can access from indoors a repeater 50 miles away. Not bad for such a tiny radio running 2 - 3 watts. Several people who have bought the UV-3R have commented favourably on the performance of the supplied single-band antennas. I tested the VHF antenna and found an extremely sharp response curve with a perfect 1:1 SWR at about 143.5MHz. At 145MHz the SWR was 1.5:1. The antenna has a high Q which no doubt accounts for its surprisingly good performance for its size. It's a pity the resonant point isn't exactly on 145MHz but that would be difficult to achieve with a mass produced antenna.

It isn't perfect, but all in all I am pleased with the tiny little Baofeng UV-3R - for the price. However there are indications that where quality is concerned you are getting what you pay for. If I was a UK dealer thinking of importing a batch to sell I'd think twice. I think fussy British consumers would send quite a few back because of niggling faults like the non-working TX indicator or the problem with the headset/mic. But if you don't mind taking a bit of a gamble on buying a radio from Hong Kong then the UV-3R would be a good bet for £25.

Handheld receiver blocking shootout

Ever since my outing on to Ling Fell yesterday I have been bugged by not knowing for sure whether the problems I experienced with the VX-8GR were really caused by receiver overload or blocking. I like the construction and features of the Yaesu. But a radio that makes you miss some of the contacts you have laboriously sweated up a summit to make is about as much use as a chocolate teapot. I wondered if I could devise a test to give me an idea of the relative strengths of the different 2m radios. I did, and the candidates are lined up in order of merit below, the worst on the left and the best on the right.

The test methodology was crude. I connected each radio to my dual band vertical and tuned in a weakish station: the GB3AS repeater on 145.600MHz, which is normally an S3 signal - fully readable but with some background noise on the audio. I then transmitted a carrier on 144.025MHz using another radio on a helical antenna a few metres from the vertical. I tried two power levels of the interfering signal, 3.5W ("high power") and 0.5W ("low power"), these being the available power levels of the test radio. This 8dB difference in the interfering signal level had different effects on the ability to receive the repeater signal.

I am well aware of the limitations of the test I carried out. In real life SOTA or WOTA use a radio may be subjected to strong in-band signals from activators on other summits but they will not be as strong as the signal from a radio a few metres away from the antenna. A radio is likely to be subjected to strong signals from outside the amateur band such as pagers and other commercial signals, which the bandpass filters in modern radios due to the marketing-driven necessity of providing wideband receive coverage will do nothing to attenuate. Many strong signals may mix together to cause intermodulation effects if not blocking. However, a receiver that can handle a strong in-band interfering signal is likely also to be better at coping with many strong signals being received over a range of frequencies. So I think my test results have some validity.

Beginning with the worst receiver, the results are as follows.

• VX-8GR. This receiver was the worst affected by blocking. Noticeable desensing of the repeater signal occurred when the in-band carrier was on low power, while a weak noisy "4 by 1" signal was killed completely. The repeater signal cut out completely when the in-band carrier was keyed on high power. Engaging the RX ATT (menu option 1) caused the repeater signal to drop below the squelch threshold so it was not much help though it did reduce the desensing effect on stronger signals.
• JMT-228. The VX-8 was slightly worse than the Jin Ma Tong JT-228, a £30 Chinese handheld bought on eBay. In fairness, the JT-228 is slightly less sensitive than the Japanese ham radios (judging by the signal to noise ratio on weak signals) which may have helped it a bit. Desensing was noticed when the in-band carrier was on low power, and the repeater signal cut out when it was on high power.
• TH-D72. The Kenwood TH-D72 may only be third worst (or third best) but in fact it was a whole lot better. No detectable desensing occurred when the in-band carrier was on low power. Some desensing occurred, in the form of a drop in S-meter reading and increased noise on the audio, when the carrier was on high power.
• GP-300. Excellent performance was given by the Motorola GP-300. No desensing was noticed when the in-band carrier was on low power. There was a very slight but hardly noticeable increase in background noise level when the carrier was keyed on high power.
• TH-205E. I bought this old boat anchor as a "spares or repair" radio for £6 on eBay for the fun of seeing if I could get it going. With the high capacity battery pack it is about the weight and bulk of an FT-817 and not something I would particularly want to haul up a summit. But no desensing of the repeater signal was observed even when the in-band carrier was keyed on high power, making this the best performing receiver of all.

Out of interest I also carried out the test on my FT-817ND and the Kenwood TM-D710 I use as my 2m base station. The FT-817ND was slightly better than the TH-D72: there was no effect with the low power carrier but the high power one brought a noticeable background hiss on the signal. The TM-D710 performed close to the TH-205E. There was barely any noticeable effect from the high power in-band carrier.

I think the results of these tests, crude though they are, are interesting. The bigger the radio, the more likely it is to have a receiver able to handle adjacent strong signals. Paying lots of money for the latest technology is no guarantee of getting a better receiver. In fact, just the opposite. An ex-commercial handheld or a ham band one from the days when wide band receive coverage was not considered important will work better than the latest marvels.

Were it not that I find the full APRS functionality of the VX-8GR and TH-D72 useful, I'd be tempted to sell both those radios and just use a dumb tracker plugged into the mic socket of one of the others tuned to 144.800. Either I use the VX-8GR for APRS only and carry another radio for making contacts or I must try harder to love the TH-D72. Decisions, decisions. But at least I now have a bit more information to base them on.

VX-8GR receiver overload

This afternoon I went for a stroll up Ling Fell, LDW-205. It was a fine afternoon and I wanted a bit of exercise. I took the VX-8GR so I could test the new QRU feature of Lynn KJ4ERJ's APRSISCE/32 software that allows an APRS user to receive information about nearby objects on request. I have created a QRU server for Wainwright summits so that an APRS user in the fells could receive information about the nearest summits, to aid identification or navigation.

I put a 2m helical antenna on the rucksack support for the walk up, so the VX-8GR could send my position. The other channel was monitoring 145.500MHz (S20) the FM calling channel. As I gained height I started to hear some loud bursts of interference, a combination of a whine and a buzz, on S20. When I got to the top I switched antennas to the RH-770 dual band telescopic. My first call was answered by Colin, 2E0XSD. His signal was moving the meter on the VX-8GR to an S3 or 4 but there was intermittently a lot of crackly interference over his audio. I tried engaging the RX Attenuator option in the VX-8GR menu and it did seem to improve things a bit, but not completely.

A bit later, when I was testing the QRU server, I could hear the APRS packets coming back from my gateway (which is line of sight from Ling Fell, just behind me in the distance in the picture) but they sounded distorted and the VX-8GR didn't decode them.

I wondered if there was a fault with the cable to the rucksack mount so I put the antenna directly on the radio. My next call was answered by Geoff G4WHA from his car in the car park in Penrith. He was 5 by 1 but his signal was cutting out intermittently. I got the feeling the problem wasn't Geoff's, but was my receiver cutting out due to overload from some nearby transmitter. There is a commercial mast a couple of miles away on the other side of the valley, though I have no idea what is on it.

I am starting to get a feeling that the receiver in the VX-8GR is not much good on summits when connected to a decent antenna. I first noticed odd things with the original VX-8R I had when I tried it out with a SOTA Beams MFD. There have also been several occasions when other people using VX-8 series rigs on summits have failed to hear me, even though I could hear them clearly and in some cases was running much more power than they were. This is quite disappointing. I really like the VX-8GR and much prefer it over the Kenwood TH-D72 which I have been thinking about selling. But perhaps it would be better to keep the Kenwood.

I wish that I had the test equipment to try to compare the strong signal performance of my various hand held radios. HF radios have their receiver performance exhaustively tested and the results of tests by the likes of Sherwood Labs are endlessly debated on various reflectors despite the fact that the only difference it is likely to make is whether you can copy a very weak station right next door to an extremely strong one. But the reviews of VHF radios focus only on matters like the ease of use of the menu system, how many memories it has or how the scanning works.

I think the receive performance of VHF/UHF hand helds is just as important as for HF receivers. If a receiver can't cope on a hilltop on the middle of nowhere how will it fare with the signal levels in a busy urban environment? Heck, you might be missing vital emcomms messages and not know it! It's about time the ham radio magazines started publishing blocking dynamic range and cross-mod figures for hand held radios.

2m HT antenna shootout

I've been wanting to do this for a long time. I wanted to try to compare the difference between various antennas for 2 metre band handhelds so as to see how much you lose using a small inconspicuous antenna or how much you gain by using an extra long one. The results were broadly as expected. The longer the better. But there were a couple of surprises.

The efficiency of the antennas was compared using my Yaege FC-1 frequency counter, which has a relative dBm scale. I transmitted into each of the antennas in turn, noting the dBm reading on the FC-1 which was positioned a couple of metres away. This is hardly an antenna test range. However, the results were validated in on-air tests where various local amateurs were asked to report on my signal strength as I swapped antennas. The on-air results were in agreement with the measurements, which allow me to believe that they are a fair representation of the performance of these antennas in the real world.

As an aid to comparison, the performance is given as effective power out relative to a manufacturer supplied antenna driven with 5 watts. The antenna provided with the Yaesu VX-8GR is used as the reference antenna. Choosing a manufacturer supplied antenna turned out to be rather a poor reference, as although the Yaesu standard antenna performs very well, the antenna supplied with the Kenwood TH-D72 performed very poorly. It was 5dB down on the Yaesu antenna, putting it in the same range as the short stubby antennas. This is probably because the Kenwood antenna's resonant frequency, as checked on my antenna analyzer, is around 158MHz. Although it would be reasonable to suspect a fault with the antenna supplied with my TH-D72, the one supplied with my Kenwood TH-F7E (which I have since sold) was identical. If you are using a Kenwood radio then you have even more reason to throw away the supplied antenna and buy a better one.

The antennas in the picture from left to right are:

• A dummy load. This is just my little joke! Many "experts" like to say that the short stubby antennas are no better than dummy loads. In fact, my results suggest that they perform quite well for their size and are much better than dummy loads. However, as with all of these antennas, the best results depend on the antenna being resonant (having a good SWR) at 145MHz. All these antennas have quite a narrow bandwidth and if they are off-frequency it has a significant effect on their performance.
• A 2in. 144MHz stubby bought on eBay. This antenna is 5dB down on the reference Yaesu dual-band whip and would be the equivalent of reducing power on the handheld from 5W to 1.5W.
• An A-137 dual band stubby bought on eBay. I have two of these. The first one was tuned spot on 145.5MHz so I got a second one which was resonant just above 146MHz. Performance is slightly better than the single band stubby, being the same as reducing power to 2W.
• A 2m Stubby Duck from Smiley Antenna. I got this because I thought it would deliver better performance than the small stubbies while still being small enough to sit comfortably in a pocket. This proved correct. Performance is just 2dB down on the reference stock antenna, the equivalent of running 3W instead of 5W.
• A 6in. 2m helical antenna. This antenna came with the old TH-205E handheld and as far as I know is the original antenna supplied with the radio. Checked on an antenna analyzer it was resonant a few MHz high in frequency but I brought it down to 145MHz by dropping a ferrite tuning core down inside the helical and securing it with Blu-Tack. This enabled me to open a repeater I could not open before the modification, illustrating the importance of tuning these antennas to get best performance. This antenna is just 1dB down on the reference antenna, like using 4W instead of 5W - hardly noticeable.
• A Nagoya NA-701 dual band BNC antenna. I purchased this antenna as a replacement for the manufacturer supplied antenna due to my converting all my handheld radios over to BNC sockets by permanently fitting adapters. It is almsot exactly the same size as the supplied antenna and its performance is identical to it.
• An 8in. 2m helical antenna. This antenna was bought as an untuned helical which required cutting to frequency. I got it from Waters and Stanton and it is of extremely poor quality. However, the RF isn't bothered by the shoddy manufacture. It performs exactly the same as the supplied VX-8GR antenna.
• The antenna supplied with the Yaesu VX-8GR. This is the reference antenna for this comparison. As mentioned above, the antennas supplied with other radios (notably Kenwood) may not be as carefully tuned and may perform more poorly than this.
• The antenna supplied with the Yaesu FT-817ND. This is slightly bigger than the one supplied with the VX-8GR and has a BNC mount not an SMA. It performs about 1dB better, equivalent to running 6.3W. Adding the tip which makes the antenna work on 6m has no effect on 2m performance. As I have come to expect from Yaesu, this antenna is resonant precisely on 145MHz, as was the one with the original FT-817 that I had many years ago.
• A quarter wave telescopic BNC whip. These 19in telescopic antennas are available from a variety of sources. I think this one came originally from Maplin. It gives your signal a 3dB boost, equivalent to doubling your output power (and doubles the received signal strength also.) At a cost of £8, it is a cheap way to double your effective power and not too long to be cumbersome in use.
• A Nagoya NA-767 bought on eBay. This is a dual band telescopic antenna which is 38 inches (97cm) long when extended. It has a heavy metal base which presumably contains a loading coil. The BNC connector is made mostly of plastic, but the base is sprung which should take some strain off it. The telescopic sections are quite stiff. The build quality of the antenna is not great but it is quite cheap. The performance gain is substantial, giving a 4 times power boost over the quarter wave antenna, equivalent to running 40 watts output.
• A Sharman RH-770 dual band antenna bought from Capital Stores. This appears to be a clone of the Diamond RH-770 which is sold at the usual rip-off prices by certain ham radio dealers. The Sharman version is half the price. It is a dual band antenna with centre loading and is 93cm (36 inches) long when extended. It looks and feels a better quality antenna than the NA-767. It also performs slightly better on 2m, giving your handheld a full ten times gain on transmit and receive compared to the supplied rubber duck. It's the equivalent of running 50 watts from a handheld!
• Not shown in the picture is the 45.5inch Black Whip from jeepbangkok on eBay. This is a 5/8 wave single band (2m) antenna and was the best performing handheld 2m antenna of all, giving 11dB of gain over the manufacturer supplied whip, the equivalent of running 63 watts of power! Sadly the telescopic whip was of poor quality and pulled apart during a recent WOTA activation.

Clearly one should not use such long antennas as the last three on a typical modern handheld radio with SMA antenna socket unless you are using a stout SMA to BNC adapter that tightens down to rest on the body of the radio so that no twisting moment is applied to the SMA socket. Even then, you may rightly be wary of using such a long antenna in the windy conditions often encountered on Lake District summits, which often bent the sprung base of the Black Whip into a 45 degree angle. Because of this I have made up a rucksack mount with a BNC socket and a 19in. quarter wave counterpoise so these high gain antennas can be used off the radio.

I was unable to test the free standing WOTA Pole (ribbon cable Slim Jim inside a plastic tube) under the same conditions but on-air reports suggest that it may give even more gain than the Black Whip. However, it isn't always convenient to set up a guyed antenna on a summit, so one of these telescopic high gain antennas could be the answer to improving your signal when using a handheld radio.

These test results have related exclusively to the 2m band. I do not have test equipment that works up to 440MHz, nor is there any activity on 70cm in this part of the world so I have no plans to compare the performance of these antennas on UHF.

Getting the plot

A few years ago I read about a program called Radio Mobile which was supposed to be able to plot maps showing your VHF or UHF station coverage using actual terrain data. I downloaded it but couldn't figure out how to get it to work so I gave up. A few days ago someone mentioned that it is possible to hook the program into an APRS server so I thought that I would try again. I was given a hint that for UK users the G3TVU Quick Start package was the easiest way to get Radio Mobile going.

The default setup is for a location in the Derbyshire Peak District so I followed the instructions on Changing Location to try to create maps centered on G4ILO. I got as far as producing an elevation map but was then baffled by the sentence: "Which can then be 'Merged/Copy' with a road map and 'Kept in new picture' to produce."

James VE6SRV came to my assistance with an explanation in English: "On the menu select EDIT then in the drop down menu select MERGE PICTURES... F7. You'll get a dialog box opened up. It will have a list of various sources on the left, detailed choices about the source in the middle and operation controls on the right.Try picking OSM, and then clicking DRAW. After the merge is complete, you'll be asked how you want to keep the resulting image, or to discard it. The four options equate to SAVE, SAVE AS, LET ME LOOK AT IT FOR NOW, and TOSS IT. If you chose copy, the OSM tiles will overwrite the relief map. ADD, MULTIPLY, and BITWISE are 3 different methods of merging the shaded relief map with the OSM tiles. Depending upon the colours, and the type of output you want, you'll need to play a bit with the choices to see how it looks for you. You can also play with contrast and brightness sliders to try and get the output just how you like it." This was just what I needed, and after a bit of experimentation I soon had a road map of my area merged with the relief map showing the mountains.

The next step was to try to plot the coverage of my station on the map. I believe the default setup had a dummy base, mobile and hand-held station predefined but they were now outside my area and in any case I must have deleted them. Creating a "unit" for my own station was simple enough, but when I selected one of the tools to plot coverage the Draw button was disabled. Eventually I worked out that you have to have at least two stations ("units") defined and they must both be members of the same network. The program will then plot the coverage for your station as received by a station of the same type as the other one.

I thought the coverage plots were rather optimistic judging by experience so I had to change some of the parameters and choose the "worst case" to get a plot that looked reasonable. This being VHF, it's possible that the fact of my antenna being located in the attic could result in some degradation of the signal. I felt the default colouring of green for 3dB over noise or better and yellow for 3dB below noise to 3dB above didn't give a realistic picture so I changed the colouring so that green depicts 10dB or more over noise and yellow shows between 0 and 10dB.

The first plot shows a wide area view:

Click to see the map full-sized. I did a second plot at a larger scale to show the local coverage in more detail:

The plot shows really clearly how my VHF range is limited by the surrounding hills.

Connecting Radio Mobile to an APRS server has limited use. The program doesn't seem to handle objects very well so for example the GB3CA object put out by MM1MPB shows as MM1MPB and moves that station's position. But it is a useful way to get other local stations into the system instead of manually entering their details.

The objects sent out by WOTA to show the position of a Wainwrights On The Air activation are shown as WOTA not the name of the object. The Radio Link option can be used to plot the path between two stations and estimate the received signal strength, as in this example showing the path between me and Phil G4OBK/P on the summit of Seatallan.

The estimated S9 signal strength is somewhat more than I actually received from Phil and I was running 50W not 10W. As mentioned earlier my antenna gain is also downrated over reality to try to get a more realistic picture.

Radio Mobile is a clever piece of software and it was interesting to play with it. It was quite hard work to get going, but it was useful to see how the nearby hills affect my VHF coverage.

Look out, Yaesu

Chinese-made VHF and UHF hand-held radios are no longer the novelty they were a few years ago when I discovered the Jingtong JT-208 and got one to try. They are no longer the shoddily made bits of junk the Jingtong was, either. Some Chinese makes like Wouxun are now directly imported into the UK and USA so unadventurous buyers don't have to take chances on eBay. But there are better bargains and more choices to be had if you use the auction site. When I saw a smartly styled compact VHF handheld radio transceiver 136-174MHz being sold for only £40 it looked like just the job for keeping downstairs to monitor my Echolink node and acting as a backup radio for WOTA activations so I decided to order one. Shipping from Hong Kong took one week.

The radio is a model JMT-228 and is made made by Jin Ma Tong Electronics, which is not a company Google has much information about. Whilst tearing off the wrapping I experienced a heart-sinking feeling as the box was revealed together with the description "400-470MHz." I was afraid the seller had sent the wrong model! Inspection of the manual revealed the radio comes in VHF and UHF versions, and when I looked at the back of the radio the label showed "136.000-174.000MHz." What a relief!

Together with the radio and manual, the box contains a short helical antenna, a metal belt clip, a carrying strap, a 1500mAhH 3.7V Li-Ion battery pack similar to those used in mobile phones and digital cameras, a 100 - 240V AC charger with fold-out US-style mains plug, a USB cable (presumably used only for charging as there is no mention in the manual of programming software) and a hands-free style speaker microphone terminated in a 2.5mm stereo jack.

Here is an "unboxing" video (not made by me) from YouTube:

The JMT-228 is very light (the manual amusingly gives the weight as 200kg including the battery!) and looks rather similar to the early Yaesu VX models. It's a bit smaller than the compact VX-8GR as you can see from the photograph below. The build quality seems very good. The radio is built on a die cast chassis as you can see when you put in the battery. It doesn't have quite the same solid feel as a Yaesu but the light weight is a bonus. The belt clip is metal but a bit flimsy and it is fixed to the radio using one screw. There is no retaining lug (although the clip has a hole for one) so unless you tighten the screw so hard you risk stripping the threads it could rotate allowing the radio to fall off the belt.

The glass in front of the display is actually plastic which scratches rather easily - there are a couple of dings in it already that I don't remember doing. A small thing perhaps and forgiveable at the price but something many hams won't think about as we take the high quality of ham radio products for granted.

No claims are made that the radio is waterproof. Indeed, the manual warns: "Never expose the transceiver to rain, wet areas or any liquids, or it may be damaged. However, the speaker/mic and USB/charger sockets have stout rubber covers and another page in the manual states: "The transceiver is not fully water-resistant while using the speaker/microphone" which implies that it could be. The JMT-228 certainly doesn't look any less waterproof than the Yaesu VX-8GR so it could probably withstand the odd rain shower, but don't quote me on that as I haven't tried getting it wet just to see what happens.

The manual is in Chinese and English. The English part is well written for a Chinese radio, though the most important part, describing the "Auxiliary Fuctions" (sic) is squashed into two pages and less well written so you need to do some guesswork to determine some of the functions. RC sets the CTS or DCS tones for receive, TC sets them for transmit. TOT sets a time-out timer. OFFS sets the direction of offset for repeater use, a different menu OST sets the amount of the offset.

There are 99 memories and they store the offset and tone settings in force at the time of programming. It took only a few minutes to enter in the 2m simplex channels, the three local repeaters and my Echolink node settings. Memory mode is clearly the way to use this radio on the amateur bands as it does not have automatic repeater shift as found on dedicated ham radios.

There is a scan mode, which simply scans all the memories. There is also an FM Radio mode that lets you listen to Band 2 FM radio frequencies. The sound quality isn't the greatest for listening to Classic FM or BBC Radio 3, but it's usable.

The antenna socket is an SMA type. Surprisingly for a Chinese made radio it is an SMA female, the same as that used on radios from Yaesu, Icom and Kenwood, so you can use the same SMA-M accessory antennas you could use on those radios. I can even use my SMA to BNC adapters! The supplied antenna is 4 inches long, presumably a helical whip, and fairly broadband with the best match, a 1.6:1 SWR, at 156 MHz. This isn't going to be optimum (tests I have carried out in the past have showed that a noticeable benefit is gained by tuning short helical antennas to match the frequency of use) but it is no worse than the antennas supplied with Kenwood handhelds and only to be expected in a radio designed to operate over such a wide band.

The receiver sensitivity seems on a par with other handheld radios I own. Output power is claimed to be less than or equal to 5W. Frankly, I would not expect to get 5W out of a radio powered by a 3.7V battery pack. If you did, it would get very hot very quickly and the battery would soon run out. I measured the output power at 3W which I think is very good for a radio of this size. I had no trouble opening the GB3LA repeater more than 50 miles away using a 7 inch long helical (but not with the supplied antenna.)

There is no low power setting, which is a bit of a disappointment and will not help battery conservation. On receive, however, the radio seems to run forever, helped no doubt by a quite severe power saver mode. This does not appear to be user configurable nor can it be disabled so you could not use this radio to receive packet or APRS.

The modulation using the internal microphone is OK, but a bit on the low side. Using the included speaker/mic it is a bit better. Note that although this speaker/mic is similar to a hands-free mobile phone kit, the JMT-228 transceiver does not have VOX, so it is necessary to key the transmitter by pressing the button on the back of the mic. Here are some audio recordings of the JMT-228, with a couple of other hand-held radios for comparison purposes.

• JMT-228 using internal microphone
• JMT-228 using provided external speaker-mic
• Old Trio/Kenwood TH-205E with internal mic
• Motorola GP300 with internal mic

As you can hear, the audio level is similar to the Motorola GP300, another radio designed for use on the professional high bands. Amateur band radios tend to have a higher modulation similar to the TH-205E.

When using the speaker/mic I found that the transceiver tended to lock in transmit - presumably due to RF getting into the speaker/mic cable which is right next to the antenna. This is a bit of an annoyance, which could possibly be cured using a really small snap-on ferrite if I had one.

Despite a few niggles I think the Jin Ma Tong JMT-228 transceiver is a nice little radio and would be a good buy for anyone wanting an inexpensive and compact transceiver for use in the amateur 2m band. I think the Chinese are going to own the market for basic single or dual band handhelds very shortly and people will only buy from the specialist manufacturers if they need specialist functionality such as APRS, wide band scanning, a short wave receiver or even, dare I say it, D-Star.

Back to the drawing board

The weather forecast wasn't promising, even though the morning was fine. But I was keen to get out on the fells. Yesterday I spent a couple of hours making an antenna specifically for Wainwrights On The Air operating and I wanted to try it out. So I headed for Broom Fell, LDW-169.

I'd had the idea for this antenna for a couple of years but hadn't got around to making it. I was going to call it the WOTA Pole. As, for reasons I will come to, I'm unlikely to be publishing a detailed description of it, I'll give you the outline of it now. It's a Slim Jim made from 300 ohm flat ribbon cable, housed in a tube made of white UPVC electrical conduit. The tube breaks down into four sections for easy carrying using UPVC jointing pieces. It's a similar idea to the SOTA Beams MFD except that is a half wave dipole and has a T piece with a coaxial balun and can be used vertically or horizontally. The Slim Jim should theoretically have some gain over the dipole but it can't be used horizontally, which is no disadvantage as 99% of WOTA activating is done on FM.

One reason I haven't used the MFD very much is the difficulty in deploying it. The antenna is provided with two velcro straps so it can be attached to a convenient fence post. Unfortunately our hilltops don't often have convenient fence posts on the summit. My intention with the WOTA Pole had been to stuff the antenna in my rucksack for support so the radiating element would be above head height. Unfortunately UPVC jointing pieces aren't very strong and it's impossible to lift a rucksack onto your back whilst keeping a 2 metre long antenna perfectly vertical to minimize the strain on the joins. As I lifted it up I heard a crack and the antenna fell to pieces!

I didn't see any damage. It was quite windy up there and I thought the culprit was the wind, plus perhaps I hadn't pushed the jointing pieces tightly enough together. So instead I decided to strap the antenna to a convenient fence post which fortunately Broom Fell just happened to be equipped with right by the summit cairn. You can see the result in the photo. Lords Seat is the fell on the right in middle distance, with the Skiddaw range further away on the left.

Sunday lunchtime is not the best time to go WOTA activating. I think many chasers are busy filling themselves with roast beef and yorkshire pudding and nowhere near their radios. However Colin 2E0XSD was on frequency having been following my progress via APRS. He gave me a 59 plus report on the new antenna. After a couple of fruitless CQs I started to think that was going to be the lot, then Geoff GM4WHA came up, followed by Malcolm M0XAT. Then no-one. As the wind was bending the WOTA Pole rather a lot I took it down. I then tried a couple more calls using a helical antenna and got Mark MM1MPB and Tony G1OAE. Finally Colin 2E0XSD came up again to say I was only 4 by 3 on the helical antenna. The WOTA Pole had made a huge difference. It's just a pity there hadn't been anyone further afield listening at the time.

I walked down the hill a short way to get out of the wind and have the sandwiches and coffee that Olga had made for me. While I was down there I thought I would have another try at hoisting the antenna on to my back in the rucksack. Then I noticed that one of the UPVC jointing pieces - the one at the top of the lowest tube that takes most of the strain - had cracked. When I tried to get it aloft a piece broke away completely and the antenna fell to the ground. Another idea bites the dust. Literally!

On the way down I was pondering what I could do to make this idea work. Clearly the Slim Jim itself performed very well. In fact if anything it worked a bit too well on receive. The VX-8GR receiver exhibited clear signs of overload. I'd noticed this before when I'd used that radio with the MFD. I should really use the Motorola GP-300. Ironic that a radio that cost me £1 at a rally works better than a fancy Yaesu costing more than £300!

The problem with my WOTA Pole idea is the mechanical design. If I'd made the tube two one metre pieces instead of four 50cm lengths it would be stronger. But having something sticking 50cm above the top of my rucksack would be a nuisance when walking under low branches or ducking under fallen trees as I actually had to do on this walk.

Perhaps I should give up the idea entirely and try to make a rucksack mount for BNC fitting antennas. Then I could use the telescopic 5/8 wave that I usually use on less windy days fitted directly to the radio. What do you think?

Sporadic-E on 6m

The first bit of live data I received from my APRS VHF propagation alert reflector was a warning of a possible Sporadic-E opening on six metres. I was rather surprised that there was Sporadic-E this early in the year, but I went to the DX Sherlock website and sure enough contacts had been reported between a station even further north than here and one in the Czech Republic. I then clicked on the map to see the actual contact details and was surprised to find they were WSPR spots!

I went to the WSPR website and sure enough the same signals were shown. I decided to fire up WSPR on 6m myself but by then the OK station had gone and no new spots appeared from anywhere.

I have been, and still am, somewhat sceptical of the value of WSPR in showing VHF Sporadic-E propagation. One of the characteristics of Sporadic-E, particularly at the start and end of the season or on the higher frequencies like 2m is that it is very fleeting. A signal can be there for one minute, literally, and gone the next. On the other hand, signals can be really strong when reflected by Sporadic-E. WSPR is designed for detecting weak signals under steady propagation conditions and uses a 2 minute transmit cycle during which the data is transmitted very slowly. It seems to me that what you want to detect Sporadic-E is a mode with short transmit cycles where the data is transmitted quickly, perhaps something more akin to the modes used for meteor-scatter. I wonder if K1JT could come up with something?

Nevertheless I am very interested in anything that helps to detect VHF openings that might otherwise go undetected. I plan on WSPRing more on the 6m band, as long as there are others doing likewise so there is a chance of being received!

VHF propagation alerts over APRS

I have just set up an ANSRVR notification group (the APRS equivalent of an email reflector) called CDGVHF. The purpose of the group is to alert interested subscribers in the Cumbria, Dumfries and Galloway area to possible openings on the 6m, 4m, 2m and 70cm bands.

The APRS alerts make use of the email alert service of DX Sherlock which sends alerts of possible band openings customized to the subscriber's location, based on DX Cluster spots and other reverse beacon information. I have set up a subscription to send alerts of possible band openings workable from the IO84 grid locator to a special email address on the G4ILO's Shack web server. Using a feature of the cPanel web hosting, the email is "piped" to a script written by me in the PHP language. This extracts the subject header of the email which contains a succinct description of the alert, shortens it as much as possible and then sends it as a message to the CDGVHF ANSRVR group, which then forwards it to all interested subscribers.

Why is this better than just subscribing directly to receive the alert emails? Because I can now receive the alerts on my APRS-equipped hand-held, which should greatly reduce the chance of missing a good band opening because I wasn't in the shack at the right moment.

K144XV comments

The K144XV eventually turned up late on Thursday afternoon. After the board modifications had been performed, installing the transverter module was easy following Elecraft's exemplary instructions. I had to remove the KIO3 module in order to remove the KXV3 transverter module and replace it with the KXV3A, which has a couple of additional connectors for the internal transverter, then replace the KIO3. I also had to replace the side panel of the K3 with one that has some extra holes for securing the transverter. The stiffener that runs across the top of the case is also replaced by one with a cutout where it passes over the K144XV.

Due to the lateness of the hour I was a bit tired and also focussed on getting the job finished so the shack could be restored to normality so I never even thought about taking some pictures. The module comes as a complete screened box not a bare board as shown in some of the pictures on the Elecraft website. It is quite a little beauty and the way it all fits into the K3 is a work of art.

Although described as a 10W module the instruction manual states that you should get at least 9W with 1.0mW input to the transverter. I actually got about 11W so the power output comfortably exceeded spec. At my noisy location I can't make any meaningful observation about sensitivity - any half decent 2m radio will be sensitive enough. But I did notice that S meter readings are extremely low. I see no movement at all on a clear frequency despite the noisy location and a repeater that lights all the signal strength bars of my TM-D710 registered just S4 on the K3. I never take any notice of S meters anyway so I'm not unduly bothered. The amplifier "brick" I will use with this has its own built-in preamp which will boost S meter readings if I want.

The 2m amplifier I have was designed to be driven by an FT-817 so it only requires an input of 5W. I found that I needed to reduce the drive to the transverter to a mere 0.15mW to achieve this level of output. I don't know how accurate the low level output power settings of the K3 are but the relationship between 28MHz drive in and power out is definitely not linear. However the signal on SSB sounded pretty clean when monitored on the FT-817.

The calibration of the transverter local oscillator is done using software, not by trying to tweak a trimmer capacitor by a fraction of a hair's breadth, which is a blessing. There are two local oscillators in the transverter to provide coverage of the full US 2m band (144 - 148MHz) using the same 28MHz - 30MHz range (interestingly the top 2MHz is not disabled in European rigs.) The transverter module is calibrated at the factory and you have to enter the calibration values into the K3 using the configuration menu. I checked the result using my FC-1 frequency counter and also my FT-817 and it appeared to be accurate to within 100Hz which is about as good as I can get. Later I listened on the GB3VHF beacon frequency and waited for the beacon to come out of the noise. I believe this beacon's frequency is GPS locked. The frequency appeared to be out by 120Hz so I was able to adjust the calibration value and get it spot on.

The signal to noise ratio on a weak FM signal is definitely better on the K3 than with my other 2m rigs but I don't see the K144XV as being the solution for people whose primary interest 2m FM. One reason is that a 2m mobile rig is cheaper and allows you to monitor and work 2m FM at the same time as using your K3 for something else. Another is that the K3 doesn't really handle channelized operation very well. The memory system has improved considerably since the early days but using the VFO to scan through memories rather than a click stop rotary control doesn't work for me, especially due to the laggy response of the K3 to the turning of the knob.

But I think the K144XV is an excellent option if you want to work 2m DX. The receiver sounds quiet and clean and having all the QRM fighting and weak signal detecting tools of the K3 available on 144MHz is a real bonus. Now I just have to wait for some 2m SSB activity to try it out!