Friday, February 25, 2011

An FM/AM/SSB handheld for 10 and 12m

I love handheld radios. The "holy grail" for me is to make long distance contacts using a handheld radio with attached antenna. Ten metres is probably the best band to achieve this. Six metres might give stronger signals when conditions are right but it is open too rarely. Lower frequencies are open more often but a practical hand-held antenna is too short and inefficient for voice contacts using low power to be possible. You can put up a ground mounted vertical or hang a dipole in the trees but then it isn't portable.

Last year I got an Intek H-520 which I used on 10m FM but although I did make some nice contacts with it I was disappointed with the radio itself. It was very power-hungry for 6 NiMH AA cells to the extent that the radio would shut down when used on maximum power unless the batteries had just been charged up. There is another problem with 10m FM in general which is that there are not all that many channels. There is a lot of QRM when the band is open, you are competing with people running a lot more than 4W to a whip antenna and in the FM mode "capture effect" means the strongest signal wipes out all others. So when I saw that a multimode handheld including SSB and covering both the 10m and 12m amateur bands was available, I decided that this was the toy for the forthcoming summer months. SSB offers the chance for some exciting handheld contacts.

The Albrecht AE2990AFS is a multimode multi-standard CB handheld radio that is readily configurable for amateur band use. There are instructions on the web and even a YouTube video on how to do the modification but the supplier included a printed copy in the box. Briefly, you pull out the rubber PTT cover which reveals five contacts next to the PTT switch. Using a soldering iron and solder wick you remove a bridge between two contacts (preferably without touching the hot solder wick on the case and melting it like I did!) then you short out two other contacts while turning the radio on. You can then choose various channel options including three for hams: Code 0 (10m + 12m switching between them using the CH9 button), Code 1 (10m band only with home frequencies 29.300 and 29.600 selected using CH9) and Code 2 (12m band only.) I chose Code 0 to get the benefit of two amateur bands.

No batteries are supplied and no charger either. The lack of a charger is a bit annoying as the charger socket is a fairly small barrel type that isn't easily obtainable (even after you've guessed the dimensions.) The battery pack takes 9 NiMH AA cells and has contacts on the bottom. A drop-in charger is available as an optional extra. I will probably make one as I did for the old TH-205E. But first I have to establish what the charging voltage is. The box the radio came in suggests the charger/DC socket on the side of the battery pack takes 12V. You can certainly run the radio off that, but when it is switched off it draws no current. It looks as if you would have to crank the voltage up to about 18V to charge 2400mAH NiMH cells at 240mA, which would probably have dire consequences if you switched the radio on with the charger connected. But with the lack of propagation on 10 and 12 metres I probably have a few weeks to figure it out.

The antenna supplied is about 8 inches long. I checked it using my antenna analyzer and was pleased to find that it was resonant on 28.5MHz with quite a sharp SWR curve. However such a small antenna is probably little better than useless for making contacts over more than a few miles. I have a 45in telescopic 10m antenna and that is what I plan to use with this radio.

The Albrecht AE2990AFS is ready for the new European harmonized CB frequency allocation (which the UK wants to opt out of) so the output is rated at 4W on FM and 4W PEP on SSB. The actual power measured on 10m FM from this radio was only 2.13W. This is similar to what I found with the Intek H-520. With the Intek I was able to get inside, find the power adjuster and tweak it up to 4W. That's when I discovered why it had been set lower in the factory - the current draw at 4W is just too high for many AA rechargeables to sustain. Most CB users would never know their radio was giving less power than claimed because they have nothing to measure it with, so they would never complain. If it cut out whenever they press the PTT then they would. We hams complain that our radios are expensive but they are built to a higher standard than CB radios. You get what you pay for.

With its 9 cell battery pack the Albrecht doesn't need to draw so much current as the Intek for the same power. While it was on the bench power supply I measured the current draw on FM "high power" (2W) as 800mA. On the low power position which is meant to be 1W but was actually 0.51W the draw was 500mA. Unlike the Intek there is a "warranty is void if you remove this" sticker over the two halves of the case so I can't delve inside undetected. As I have heard of people who bought similar radios under other brand names which broke and had to be returned under warranty I don't want to void it, so I'll have to live with 2W output, at least until next year.

On SSB the modulation out of the box was almost nonexistent. This is dependent on the mic gain setting, which can be adjusted from the front panel. After increasing it the SSB modulation was much improved and although I don't have a peak reading meter the average level gave me to believe I was getting 4W PEP.

The audio on SSB sounded clean but if you increase the mic gain in order to get reasonable talk power there is noticeable frequency modulation on the signal. I am guessing that the battery voltage sags a bit on speech peaks and this pulls the local oscillator. I had read about this issue in some forums discussing the other incarnations of this radio and someone stated that in the Albrecht versions this problem had been fixed. It appears this may not be the case. I doubt that the fault would make the audio unreadable but I would expect to receive comments about it.

I recorded a number of audio samples at different mic gain settings for comparison. You can hear the FM increase on voice peaks as the mic gain increases.
When configured for ham band use the radio displays frequency as you would expect. The display has an attractive blue backlight. Tuning is by up/down buttons at the side. There is an annoying beep at every button press, but this can easily be silenced. The standard tuning step is 10kHz which is a bit large for convenient band scanning. You can change the step size for fast or slow tuning - the steps are 100kHz, 10kHz and 500Hz. The 500Hz step size is still a bit large for satisfactory SSB tuning. There is a clarifier control but it works on receive only. So some people you call will complain you are off frequency.

There are five memory channels which store frequency and mode, so you can switch quickly between FM and SSB calling frequencies for example. You can select a shift or offset of up to 990kHz for repeater use. There is also a CTCSS tone for repeater access, but the manual implies it is a fixed 88.5Hz tone which (apparently) is used by 10m repeaters in the USA. This is straight from the manual - I can't vouch for it.

With the lack of any propagation on 10 or 12 metres I obviously haven't had a chance make any contacts with the radio or evaluate the receiver sensitivity. The RF gain and squelch sensitivity can also be adjusted from the front panel in the same way as the mic gain. There is even a roger beep!

So there you have it. The below-specification power and FM-y SSB audio are fairly major faults, all things considered. But the Albrecht AE2990AFS is the only true handheld SSB-capable radio for any amateur band currently available. If that's what you want, it's your only option.

16 comments:

Paul - PC4T said...

hello Julian, I like handhelds, just for fun and the possibility to take it with me on holidays, at the swimming pool. When the solar peak is coming in 2012 and 2013, then it's good DX-ing on 12 or 10 meter, then with only 2 or 3 watts. I like the mic gain at level 7, the other have a little of distortion. 73 Paul

PE4BAS, Bas said...

Hello Julian, there are more handhelds with SSB for use on 10m. However they do not cover the 12m. And are also modified from CB. Recently I read a article in a CB forum that the chinese manufacturing the Dragon SS301 and the Magnum 1012. Both capable of 12 and 10m. The thing is.....that they are exactly the same as your Albrecht. Only the price could be lower I presume. It would be a thrill if you work USA some day with you telescopic whip and the Albrecht on a sunny day at a hilltop. I guess you'll wait till there is some more activity from the sun ;-) 73, Bas

Julian said...

Yes, to work the USA with a radio like this would be the ultimate achievement. Sunspots, please!! In the meantime I will be happy just to work into Europe.

I'm sure you are right that this is made in China even though it claims to be made by Alan in Germany. I wish one of the ham manufacturers would step up and make an HF SSB radio in handheld format. The FT-817 is a much better radio but it is not such a convenient format.

Paul - PC4T said...

Hi Julian, it must be possible, I worked in the seventies the West Coast of the USA with 2 watt SSB on 20 meter. 73 Paul

Peter said...

I've been reading about this radio on a number of websites. A lot of people mention the distortion or shift in SSB modulation. I was reading trough some Geman internet forum and found this interesting link, an official service note with a mod (replacement of a capacitator) to fix the distortion or jitter. service.alan-electronics.de/CB/AE2990AFS/Service-Note-AE2990AFS-Febr21-2011.pdf

Julian said...

That's a good bit of detective work Peter. Handy if you read German. Now I have a dilemma - if I do the mod myself then I must break the seal and void the warranty and if anything goes wrong that I can't fix I've had it. So I suppose I should send it back to have the mod done.

Mads said...

Hello Julian

I'm sorry I was not able to work you during my stay in Keswick last week.

This radio looks very interesting. Did you purchase it from Ebay or from a local dealer? They are very expensive in Norway (£275) and much cheaper in Germany (£185).

73! Mads

Julian said...

Hello Mads.

Yes I am sorry I was not able to hook up with you. I listened for you when you were on the "pudding basins" but heard nothing. The following day when you were on Lords Seat I was having problems with my internet connection so I missed all the spots.

I bought this radio from a UK dealer. I was tempted to buy the same radio under another name for less money from an eBay seller but I have read of a few cases where buyers had problems so I decided it was better to buy from the UK in case I needed to use the warranty.

I dare say I'll be using it quite a bit from the SOTA summit Watch Hill during the summer, which as you know is almost on my doorstep.

Tim said...

That looks an exciting radio, Julian! Like you, I love the possibilities a handheld affords, particularly on bands like 10m.

I look forward to hearing how you get on!

73, Tim, G4VXE

Marty said...

How do you shut off the annoying beep?

Julian said...

It's in the manual, but I've had so many emails about it I've written the instructions here as well.

Paul said...

If you really want to make handheld DX contacts, build this:

http://www.alexloop.com/artigo9.html

Julian said...

That's an interesting idea to try, perhaps a project for the summer. However from my experience with the small portable magnetic loop I made a couple of years ago I'm not sure there would be much gain over the base loaded telescopic with counterpoise. I also think that holding the magnetic loop so close to the head as in the second picture would detune the loop. For best performance I should think you must hold the radio at a distance and use a speaker-mic.

Andrew Baker said...

HI JULIAN . THESE RADIOS ARE MADE IN THE PHILIPPINES MATE. I'VE ORDERED SOME PARTS FROM THE FACTORY WHERE THERE MADE. HAD PROBLEMS LIKE YOU DESCRIBED WITH SSB AUDIO FM'ING . THERE IS ALSO A REAR BOARD ATTACHED AND THE NEWER NODELS HAVE THE TX AND RX CLARIFIER FOR THE SSB. THE REAR BOARD ASSEMBLY I PURCHASED KNOCKED ME BACK £35 BUT THE DELIVERY WAS BY DHL AND PUMPED THE PRICE UPTO NEARLY £100. WITH THE IMPROVED REAR BOARD THERE WAS NO FM'ING ON SSB . BUT THE LOW POWER WAS THE SAME ON FM AND SLIGHTLY HIGHER ON SSB

Julian Moss said...

Looks like it would almost be better to buy a new radio, Andrew.

Andrew Baker said...

yes your right julian , just thought i'd leave the info . someone out there may of needed some replacemant parts. but to be truthful now , as you say better to buy a new radio . they have come down in price now. just thought the update with it being a philippino radio rather than chinese . will be going to the philippines december this year , so might stop by the factory to see if i can get hold of some spares . be better than having to pay the rip off dhl fees , and then that ridiculous import fee as well.