AmateurRadio.com

One of the things I had intended to do this year was install the external frequency reference module in my Elecraft K3 in order to get the best possible frequency accuracy for digital modes. To this end I had ordered an Off-Air Frequency Standard (OAFS) kit from Spectrum Communications so as to avoid wearing out my rubidium frequency standard. I had completed populating the OAFS board a couple of weeks before I ended up in hospital. So I thought I would try to see if it worked, as that would simply involve connecting up a speaker, ferrite rod antenna and power supply.

It began to look as if the predictions of the couple of people who commented or emailed when I first posted about the OAFS were going to be right. I could hear BBC Radio 4 long wave in the loudspeaker but it was very weak, presumably (as I had been advised) due to North Cumbria being a poor location to receive the transmission. When I checked the frequency of the phase locked loop it remained steadfastly on 216.4kHz regardless of the setting of the trimpot.

The instructions supplied with the kit suggested that it might be necessary to change a resistor value if the loop will not lock on to 198kHz so I wrote to Tony Nailer at Spectrum to see if he had a suggestion. Unfortunately his reply was that if the loop will not change frequency with the pot there must be a solder bridge or other assembly error. I checked my soldering as best I could and re-did any joints that looked suspect but the way my eyes are now any sort of cross checking between the schematic and the circuit board to look for errors is impossible.

I haven’t really figured out what is wrong with my eyes but it is as if they no longer have the ability to vary focus. I can only see clearly what is at the exact focal point of whatever spectacles I am wearing. When something is out of focus my head swims and I have to close my eyes for a few minutes to steady it again. So any sort of constructional work now is well-nigh impossible.

Tony offered to get the OAFS working for me for a fee if I sent it to him, but at this point I think it would be a waste of money. I can’t see myself installing the frequency reference boards in my K3 now even if I still had the same interest in doing so. So I think the OAFS is destined for the G4ILO junkbox.

I recently resurrected the 50-MHz transverter project and have made good headway getting it working.  On Friday night, I began the process of tapping holes in the PA module heat spreader.  But, despite using plenty of “cutting fluid” (3-in-1 oil), I managed to break a (well-used) tap on the first hole.  Since the maximum (linear) power out of the driver stage is 200 mW, I embraced my inner QRPer and put the PA project aside to give the transverter a try in the CQ WW VHF contest.

The 6-meter Yagi had come down in favor of Yagis for 222 and 432 when the loaner FT-736R showed up.  So, I scampered up onto the roof and moved Yagis around.  I had hoped that this moment would be accompanied by changing out RG-8 coax for LMR-600 and LDF4-50A that are taking up space in the shop and shack.  But, I was not ready to commit to cutting that and I still don’t have LMR-600UF for the rotator loops.  Plus, I should replace the rotator at the same time.  That amounted to too much work for the available time.  I really just need to bite the bullet and install a rotating mast for the VHF antennas that’s not so precarious.

Got everything hooked up late on Saturday afternoon, but had to tend to some domestic concerns and was QRT until later in the evening when I heard my neighbor W4EE calling CQ on six SSB.  Did not know that he had six!  Apparently, this is a new thing for him, too.  He was surprised that I didn’t vibrate his radio off the desk like I usually do!  Told him I was running 200 mW and everything made sense.

Ended up working a few other locals on Sunday including N3UM, who moved me from 6-meter CW to 2-meter SSB for a quick chat.  He just completed the N1DPM active bias mod to his Mirage B2518G, so was eager for an audio report.  Sounds good!  He said my B3016G sounded good on-frequency, but I haven’t gotten the mod actually inserted into mine yet.  Probably that Kenwood (TS-700S) audio making up for the amp’s inferiority…

Eventually, I will be posting more details on the circuit here.  This is one of those projects that I would not encourage anyone to duplicate as I have constructed it.  However, there may be useful features.

Hidden in a nondescript mountain location in eastern Pennsylvania, the highly trained squirrels at the Radio Artisan Lab have been working feverishly lately on the Arduino keyer code.  Besides being amazed that squirrels can code in C or even operate computers in the first place, I’m amazed at some of the features they’ve been pumping out. Here are the highlights:

You can now plug a PS2 keyboard right into the keyer, no computer required.

The keyer interfaces with popular logging and contest programs with the new Winkey Emulation feature.

Iambic A and B modes are now available.  Straight key and bug modes are also available as before.

Various timing niceties like wordspace adjust, keying compensation, autospace, and first element extension are now available, along with the existing PTT lead/lag and dit-to-dah ratio features.

There’s now a Dead Operator Watchdog.  If you keel over mid-QSO and one of the paddles gets stuck, the keyer will stop transmitting so you won’t be QRMing the frequency until your unfortunate (or fortunate) XYL finds you.

A few months ago one of the bright-eyed and bushy-tailed new guys wrote some Hellschreiber code on his lunch break.  I’m not sure anyone will use it, but it’s there if some one wants to build a hell beacon or respond back to an unsuspecting CW op in hell.  [insert joke here]

The little rodents tell me there’s more coming.

Series Four Episode Fifteen of the ICQ Podcast has been released. News Stories include :-

• RS-ID via linked repeaters results 
• Space trash misses hams
• Amateur Radio Satellites 50th Anniversary 
• New Whipbeater antenna 
• Portugal allocates additional 5 MHz frequency 
• 500 kHz for Malta
• UK spectrum management 
• Rare satellite grid squares activated
• Satellite Beginners Workshop 
• Scottish Scout New Horizons Expedition 
• Olympic tests on 70cm 
• Amateur radio repeater falls silent 
• Amateur bags classic callsign 

Your feedback, North American HamBrief with Chris Matthieu (N7ICE), American licence system by Jon Hawkes (VK2TCW and K2TCW) and Martin (M1MRB) discusses our mini holiday dxepedition.

Series Four Episode Fifteen of the ICQ Podcast has been released. News Stories include :-

• RS-ID via linked repeaters results 
• Space trash misses hams
• Amateur Radio Satellites 50th Anniversary 
• New Whipbeater antenna 
• Portugal allocates additional 5 MHz frequency 
• 500 kHz for Malta
• UK spectrum management 
• Rare satellite grid squares activated
• Satellite Beginners Workshop 
• Scottish Scout New Horizons Expedition 
• Olympic tests on 70cm 
• Amateur radio repeater falls silent 
• Amateur bags classic callsign 

Your feedback, North American HamBrief with Chris Matthieu (N7ICE), American licence system by Jon Hawkes (VK2TCW and K2TCW) and Martin (M1MRB) discusses our mini holiday dxepedition.

One of my plans for this year had been to try other bands when out activating on the fells. I was going to try 4 metres. Many SOTA activators use 4m FM already and the introduction of new hand-held 4m radios from Wouxun seemed likely to cause a surge of interest in the band. Moreover, 70MHz offered the prospect of chance long distance Sporadic-E contacts during the summer months which has always been one of my main interests.

I decided not to get one of the new Wouxun radios, however. Whilst the new 4m/2m dual bander looked tempting, I didn’t need another hand-held with 2m capability and any dual band antenna would be an undesirable compromise. The single band 4m Wouxun was almost the same price as the dual bander, so was not a good deal. Instead, I had a look to see if I could find something like a low band version of the Motorola GP300. I couldn’t, but eBay turned up a professional radio called the H112PLUS made by Cybercom Electronic Corporation Limited in Taiwan, available in VHF low band, high band and UHF versions for just over £50 shipped. A particular attraction was that the radio claimed to conform to IP54 weatherproofing specifications – useful when operating from rainy fell-tops.

Unlike stuff from Hong Kong or China, the “expedited shipping” method used to send the radio attracted the attention of UK Customs so delivery was delayed by over a week and I had to pay an additional £25 tax and ParcelForce collection fee to receive it.

On opening the box I was extremely impressed with the very high quality of the product. This was one of the most beautifully made hand-held radios I had seen. As far as build quality is concerned this is the opposite end of the spectrum from the little Baofeng. However the little Chinese radio is miles ahead when it comes to usability and performance. The H112PLUS is about the same size and weight as the Kenwood TH-D72 so it is one of the chunkier hand-helds. Programming software, cable and a desk charger are included in the price.

So to the shortcomings. The knob on the top is a rotary control marked Vol/Ch but in fact it only controls the volume in discrete steps. Most of the time when you turn it, nothing happens. It is as if the CPU in the radio is asleep and doesn’t notice you operating the controls for a while. The buttons on the front panel, which are used to change channel and access menu functions, are also a bit laggy in operation. If you try to hurry the radio, the firmware locks up and you have to pull the battery pack. The programming software is also a bit flaky and locks the radio after writing to it, requiring another battery pull.

By the time I received the low band radio I was awaiting an appointment for a scan for my as yet undiagnosed brain tumour and was a bit anxious. I was wondering if I would ever make a 4m contact and so, rather stupidly but with the aim of having something to look forward to I ordered a second, high band version to use on 2m. This arrived after I was out of hospital and attracted a £30 tax and collection fee despite being exactly the same price.

The high band version suffers exactly the same shortcomings as the low band one but as it covers the 2m band I was able to try it out. The main problem I noticed is that it has probably the worst receive audio of any hand-held I have used. There is a compression option which appears to clip the audio and make it sound like those police radios but even with this off the audio is still quite distorted and the actual volume from the speaker is not all that loud. The little UV-3R is much louder and sounds much better!

The programming software allows you to set power level (high/low power) frequency and CTCSS/DCS tone so you can access repeaters. There is no 1750Hz tone burst, of course, and no option I can find for setting the squelch threshold. There are scrambler options that are no use on the ham bands. I then discovered a bug. If you program separate transmit and receive frequencies (as for a repeater) and then save the results as a file, when you load the saved file the frequency splits are lost. The developer has acknowledged the bug and has promised a new version of the programming software.

The output power is about 5W on the low band radio and 6W from the high band one. The battery pack is NiMH and rated at 1500mAh. Someone has told me it is identical to one made by Kenwood. Battery endurance, even on standby, is not great.

When ordering the low band model you are given the option of specifying one of two frequencies for the helical antenna. I chose 69MHz. On the antenna analyzer the best SWR coincided exactly with 70.45MHz, which was rather nice. However the ERP from the helical is about 5dB down on a telescopic whip. The high band radio comes with a short helical that is resonant on 150MHz, but you can pop the cap off and add a few turns to the spring to get it down to 145MHz. The antenna socket is TNC so you need an adapter to use most other ham radio antennas. The speaker/mic two pin jack uses the Icom/Maxon standard.

The radios do work. I even had a 4m contact with a Scottish contest station during VHF field day. Given my health situation I have not had the opportunity to test these radios out in the field with good external antennas to see how they stand up to the high levels of signals encountered on hilltops. However, I attempted to reproduce the test I carried out in the Handheld receiver blocking shootout and the 2m H112PLUS was as bad as the poorest receiver I tested. The received repeater signal cut out when a signal at the bottom of the 2m band was keyed up, when most other radios under the same conditions showed little or no desensing.

Overall I think the H112PLUS is a radio that is of more interest to collectors than someone wanting a real hand-held workhorse. It is well made and the waterproof specification is an attraction but the poor receive audio and flaky software and firmware are a big disappointment and I have doubts about the receiver’s ability to handle high levels of out of band signals without desensing.

The weather here ever since I was diagnosed with a brain tumour has been glorious. One of the bitterest frustrations for me has been being housebound, able to do little more than walk slowly to the shops and back instead of going for walks in the hills and activating Wainwright summits as I had planned to do. On Thursday Olga and I caught a bus into Keswick for a day out. I took along the little Baofeng UV-3R handheld in the hope of catching some SOTA or WOTA activators from the surrounding fells whilst I was there. I was pleased to make contacts with Mark MM1MPB/P and Terry G0VWP/P during the day.

I love this little UV-3R radio. It’s so small and light you can take it anywhere and the range of its 2 – 3W on the slim Nagoya NA-666 antenna I have put on it is amazing. It can receive broadcast radio so I can listen to Classic FM or BBC Radio 3 and if someone puts out a call on the 2m FM calling channel the music is interrupted and I can reply to them. The Baofeng is not ham band restricted so I have also programmed in the 8 license-free PMR446 channels and can use it to talk to Olga who has a little Goodmans set that I bought for a tenner on eBay. I can even dual watch between Olga’s channel and 2m channel S20 so I don’t miss anything.

My only niggling annoyance with the Baofeng is the audio volume level, the lowest setting of which is too high so that any station using wide FM deviation – which most folk round here do – is audible to anyone within a 50m radius. There is a mod for this, which involves putting a resistor in series with the speaker, but having tried a small soldering task a few days ago and succeeded only with a lot of difficulty I think that performing the mod would be beyond me.

I know from the Yahoo group that there is not much quality control on these Baofengs and one or two people have had the misfortune to receive radios that don’t work correctly. But for me this has been the best thirty quid I ever spent on a bit of radio gear.