A dongle for the FT-817

If you have used a Yaesu FT-817 on SSB you'll have probably been annoyed by the lack of a TUNE button to generate a steady carrier for antenna tuning. You usually have to press the MODE button a few times to select FM or PKT, use PTT to send a carrier, then change mode back to USB or LSB. It isn't one of life's greater annoyances, but it's a nuisance all the same, especially if you use an antenna like the AlexLoop which needs retuning every time you change frequency.

A couple of weeks ago I received a letter from one of my blog readers, John G4HUK, enclosing a Quick-Tune Dongle that he makes for the Yaesu FT-817, FT-857 and FT-897 rigs. It's a neat little gadget that plugs into the ACC port on the back of the radio. What it does is let you generate a tuning signal in SSB mode by double-clicking the microphone PTT. Simple but effective! It won't be so useful for home users who have a CAT cable plugged into their ACC port already, but for SOTA operators and other exponents of outdoor radio (apart from CW operators who can just hold the key down) it could be a godsend.

The Quick Tune Dongle installed on the back of the FT-817

The dongle didn't work for me at first until I set the baud rate of my FT-817's ACC port to 9600. This is explained in the 'manual'. The instructions also explain how you can reconfigure the dongle to change the way it works. By default it will use PKT mode to generate the tuning carrier and ignore double-clicks made in any mode other than USB and LSB, which I think will suit most people.

I think it is an ingenious little gadget which you can get from HUK Electronics for £15.95 + postage. Here's a video of the dongle in action.

A nice audio report

I just finished a contact with a very loud Austrian station, OE3DIA on 10 metres, who took time out while working a string of stations to give me a complimentary audio report, quite unsolicited. It's good when that happens! The comment was "Very nice audio cutting through the QRM" I was using the K3 at 80 watts and the mike was one of those Heil mikes with the dual insert, set to "narrow". The K3 transmit audio equalisation is factory standard, in other words flat.

As it happens I had just been doing some audio comparisons between the KX3 and the FT-817. There has been a thread going on the KX3 Yahoo group started by a disenchanted American ham who claims that the FT-817 has punchier audio than the KX3. It's rubbish, to put it politely. The KX3 has a built-in speech compressor, while my 817 has an RF processor made by Joachim, DF4ZS (more details on my FT-817 page) built into the microphone. Without it there is just no comparison.

I recorded some audio clips so you can hear for yourself:

• FT-817 with standard microphone, no compression
• FT-817 with standard microphone and DF4ZS compressor
• KX3 with MH3 microphone, mic gain and compression both set to 30

There is a bit of distortion on those clips which was not noticeable when listening on the radio. I think I might have a problem with my sound card.

I'm not sure if the difference are that noticeable in those clips, but when you look at the needle of the power meter the KX3 certainly has the more punchy signal.

Both the FT-817 and the KX3 were running off 13.8V and set to 5 watts output. I couldn't compare them on battery power as I don't have the charger board for the KX3 and the external battery pack (10xAA NiMH cells) I intended to use appears to be past it and the KX3 kept cutting out on voice peaks.

A day by the lake

The fine weather we have enjoyed for several weeks was forecast to change, so on Wednesday Olga and I decided to take the bus and go for a picnic lunch by Bassenthwaite Lake. For radio entertainment I took the UV-3R (in case of any SOTA or WOTA activations) and the FT-817ND.

HF conditions were pretty dire - WWV has been predicting blackouts - and I initially heard nothing above 20m. But even though I called the loudest stations that weren't calling "CQ DX outside Europe" no-one even acknowledged my existence. (What's wrong with working stations inside Europe, I'd like to know, especially when no-one is replying to your CQs anyway?)

The antenna I was using, the Wonder Wand L-Whip, could have been better. It does, however, have the advantage that it is small and light. At the moment I can't carry much, needing one hand for my walking stick and the other for balance, so everything has to fit in a small shoulder bag. So I didn't have anything else suitable.

The UV-3R produced a contact with Terry, G0VWP/P activating Walla Crag, the lowest Wainwright, prompting Olga to comment that the small radio was better than the big one!

After lunch I tuned around some more and heard some activity on 15m and 17m. And whilst tuning 17m I stumbled across this. Actually, that's what I heard a couple of minutes later after I'd dug my smartphone out of my jacket pocket to make the recording using Voice Recorder. What I heard first was ZD8D (Ascension Island) calling CQ. Repeatedly. With no takers. He was not very strong - about S4 on the '817 S-meter - with some QSB, but perfectly clear. Clearer in fact than in the recording. I called, but needless to say he didn't hear me.

As I've said before, I have little interest in working stations just to tick countries off a list. But I have a particular interest in the British colonies of Ascension Island and St. Helena as I visited both places during a "trip of a lifetime" in 1999 but have never worked either of them. Just my luck to come across a DX station calling CQ with no pileup when I'm surrounded by mountains and running just 5W to an extremely inefficient antenna!

Curse Yaesu

... for making the power connector for the FT-817 a nonstandard and apparently unique size. I sacrificed the power cable of a multi-voltage wall-wart which had a set of interchangeable tips to make a cable I could use to run the '817 from my lab bench supply for an experiment. One of the tips looked to my eyes exactly the same as the one on the Yaesu charger, even down to having a yellow plastic insulator at the tip. But stupid me I didn't think to check it would actually go in before severing the cable from the wall-wart and now I find that it doesn't. So not only did the wall-wart lose its cable in vain but I now can't do my experiement, since it would have taken longer than the '817's woefully inadequate batteries would permit. Grrr!!

I can't even find an FT-817 power cable on eBay.

EchoLink hotspot update

I just had a reply from the RSGB's ETCC regarding my NoV application. In a nutshell, applying for an NoV to use a 2m frequency for a personal short-range node is a non-starter as "it would be entirely inappropriate for RSGB to assign one of the scarce channels available within the 2M band for your personal use." However it is possible to use provisions already in the license for "remote control of your station" to operate on any frequency I choose, without an NoV. So I have asked them to withdraw my application.

As a holder of a full UK amateur radio license, there are apparently no restrictions on frequency or power that I can use for the remote control circuit (other, of course, than those that apply to normal amateur radio operation.) However the link has to be "adequately secure" to prevent unauthorized transmissions. Typically for a legal document, no specific guidance is given as to what "adequately secure" means from a technical point of view. Limiting the power - or, perhaps more importantly, the receiver sensitivity - so that it cannot receive anything other than my own transmissions might be good enough, but I certainly would not consider it adequate security for my WiFi network (though a few years ago, before everyone got WiFi equipment, I certainly used to.)

Using a transceiver that supports DCS like my FT-817 - as I am currently doing - might be considered acceptable, though it wouldn't take too long for someone to run through all the available codes and find out which one I am using. However I don't want to use the FT-817 for this forever, I'd prefer to find something cheap that I can dedicate to it, and most of the cheap ex-commercial radios don't support things like DCS. They also run too much power. So at the moment I'm not sure what the best long-term solution is.

I hate to admit it, but I can see that D-Star has the advantage here. Being digital, it knows who is calling in to the system. I presume that the DVAP Dongle has a facility to limit access to your own specific call, which would solve the security issue once and for all.

Perhaps I'm worrying too much about this. After all, the reason I'm doing this is because there is very little local VHF FM activity receivable from here. Which means the likelihood of anyone accessing my node, even if it was unsecured, is practically zero.

Postscript: I think I may have found the solution.

Calibrating the FT-817ND

A week or so ago I downloaded the latest version of K1JT's WSPR software. It has a few interesting features including a facility to set your transceiver's frequency using computer control and a way to compensate for any frequency readout inaccuracy - important when you are working within a sub-band only 200Hz wide. The process involves measuring the error at various frequencies by tuning 1.5KHz below stations of known accuracy and measuring the frequency of the heterodyne. The program will then calculate and apply the correct offset for each amateur band. However a better solution if you don't mind opening up the case is to adjust the master oscillator in the transceiver so that the readout is spot-on in the first place.

I did this first with the K3, which was easy because the master oscillator is adjusted digitally using a menu. I then decided to calibrate my FT-817ND. The reference oscillator is accessed by removing the top cover. With the radio facing towards you it is on the left hand side. The trimmer you need to adjust is shown by the arrow.

I don't have the optional TCXO module which is rather expensive, but at shack temperature the standard oscillator seems pretty stable. However, the calibration adjustment is very touchy. The tiniest hint of movement can change the transmitter frequency by as much as 10Hz at 10MHz.

I tuned 1.5KHz below WWV on 10MHz and then adjusted the trimmer so the audio frequency of the heterodyne was measured as 1500.00Hz. Adjustment was an iterative process. The audio frequency might be 1497.35Hz, then I'd nudge it up to 1497.85Hz, then the next time it would go up to 1505.43Hz and I'd have to start nudging it back again. This went on for some time, getting within a fraction of a Hz and then overshooting by several Hz in my attempt to get it spot on and having to start again. I probably spent over an hour on this and was getting a bit frustrated by the end of it, but eventually I got to within 0.15Hz which is probably as good as you can expect with an FT-817ND.

The audio frequency is measured using the computer sound card, which is not a calibrated device, and I wondered if errors in the sound card clock frequency could make this calibration method invalid. I asked about this in the WSPRnet forum and Joe, K1JT replied: "If the crystal oscillator controlling your soundcard's sample rate is off by, say, 100 ppm then your measurement of a 1500 Hz audio tone's frequency will be off by 1500 * 100 / 1000000 = 0.15 Hz. It's a pretty lousy crystal oscillator that is off by more than that. There are many ways to test your soundcard's sample rate. All of them boil down to measuring a supposedly known audio frequency. One good method: put your radio in AM mode and use WSPR's "Measure an audio frequency" button while listening to WWV, during one of the periods when they broadcast a standard tone."

I can't receive WWV that well here and I have never heard it broadcast a continuous audio tone, so for the time being I'll accept Joe's assurance that my soundcard is unlikely to be out by more than the degree of precision that I'm able to adjust the reference oscillator to anyway.

FT-817 legs it

A recent ham radio purchase that was a bit more successful was that of a pair of Palm Radio Peg Legs for the FT-817.

I'd read some good reports of this accessory and I was not disappointed. They take about five minutes to fit, which involves removing the carrying strap brackets and then replacing them using longer screws, some washers and the Peg Legs.

You have to admit that they don't just enhance the usability of the FT-817 by raising the front to a convenient angle, but they also improve the looks as well. In fact, they made me appreciate for the first time just what a nice-looking radio this is.

The Peg Leg kit comes with some spare washers, spare non-slip "boots" for the legs, and also some small self-adhesive "feet" for the FT-817 itself. As it happens, I long ago fitted some self-adhesive rubber feet to the underside of my FT-817, and the ones I fitted were rather chunkier than the ones Palm Radio supplies as you can see from the picture.

Palm claims there is no problem using a PL-259 plug in the rear socket when the front is raised. There certainly isn't with my larger feet, but with a Wonder Wand or similar antenna fitted the back rests on the antenna and not on the feet. I'll have to give up the rather precarious habit of mounting the Superantennas MP-1 directly on the back of the FT-817, as at this angle the weight tips the radio on its back. But that's a sacrifice worth making, I think.

The legs fold up to the front of the radio when they aren't needed. In this position the rig just still fits in the main compartment of the little shoulder bag I bought a few years ago in Keswick market that takes it and all the bits you need - mic, miniature key, Wonder Wand or T1 ATU plus wire - to get on the air from the field. My only complaint is that the Peg Legs and their securing screws ought to be black, to look like they were original fittings.