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Austin Amateur Radio Supply Closes
March 3rd, 2015 | 
Author: 
Texas amateur radio equipment distributor Austin Amateur Radio Supply has closed its doors.
Started by Johnny Paul, WA5BGO, SK, over 35 years ago, Austin Amateur Radio Supply had been a regular advertiser in the major ham publications. After Paul’s death in late 2013, Austin Amateur Radio continued operation for well over a year.
I bought my first HT from Austin Amateur Radio Supply 25 years ago. It’s always sad to see another small retailer close their doors.
Thank you to the Paul family for 35 years of service to our community. You are missed already.
10GHz WBFM transceivers
The modern way of getting (simply) into 10GHz WBFM appears to be using very low cost 10GHz Doppler radar modules with a 100MHz FM receiver. Whilst with G6ALB for my Pixie tests Andrew demonstrated a working 10GHz link based on these low cost modules. These are useful links Andrew sent me.
Hi Roger,These are the units I found when I was looking for [definitions of] the 10.525 GHz ISM band.It looks like 3cm Doppler radar is alive and well,I’d assumed it had disappeared in favour of PIR.Some data here:These are very good pages (for wideband FM on 10 GHz).
Andrew G6ALB
40m Pixie measurements
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| Pixie harmonic measurements |
This afternoon I visited G6ALB to do some more accurate measurements of my completed 40m Pixie kit. Power out with the 12V battery was 400mW and with a fresh PP3 9V battery 200mW. On the 12V battery TX current is around 129mA and at 9V around 83mA. 2nd harmonic rejection was about 20dB. Even the 9V output is a useful level. Maybe the cased unit should include an internal 9V battery pack which is switched off when an external 12V pack is available?
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| Pixie on the bench |
To be more useful, I should add a 7.030MHz crystal and have a switch to select this or the original 7.023MHz one. 7.030MHz is the QRP frequency. My experience is this can be quite busy.
I should also case the unit! Drilling the case could be a challenge in my current state of health! Just doing the building and testing was exhausting.
What’s the difference between the Baofeng UV-3R, UV-5R, UV-82, UV-B5/UV-B6, etc.?
In China, there is a lot of passing around of designs, tweaking, improving upon, and re-branding.
In 2011 a company called VeroTelecom brought out a “UV-3R” radio which was picked up on by Baofeng and brought to a Western market where, eager for a bargain, it went down a storm. A year later, TYT made the TH-UV5R which again was picked up by BF and released in the West as the UV-5R. Initially meant as cheap SDR business band HTs, hams quickly noticed that they have a proper VFO making them perfect for our uses.
A year after that, Baofeng (now Pofung, internationally) designed and released their own radios based on the UV-5R; the UV-82, a more “professional” version of the UV-5R, and the UV-B5/UV-B6 with an entirely redesigned and far more selective RF front-end.
The first two are pants as radios go, with all kinds of weird bugs, overloading problems, and less-than-adequate phase noise and harmonic suppression performance.
The UV-82 crossed the line from “meh” into “good” with performance being on par with existing radios twice the price.
The UV-B5 blew all existing Baofengs out of the water, with on-air performance nearly matching that of Yaesu’s lower end Vertex (VX-**) series handhelds which cost five times the price. It has its quirks but for basic repeater ragchewing its value for money can’t be beaten.
The great thing is, all these radios can be had for under $35 if you know where to look: while not perfect they are a great way to get started, or to dip your toes into the hobby without spending too much. However, if you have the disposable income to put down on a more expensive radio, do – the Yaesu FT-60R is a good start.
If you’d like to read more about the differences between some of these radios, I go into a little more detail here.
First 40m Pixie QSO
At 1000z this morning I exchanged RST 579 reports with G6ALB who is 3km from me on my 40m Pixie on 7.023MHz CW. This was my first on-air QSO. Netting was perfect and I used the rig directly into my low Par triband antenna. An ATU might have helped. Andrew G6ALB said the channel was pretty busy but that I was a good RST579 with no hint of chirp. This afternoon we’ll put the rig on his spectrum analyser. I gave Andrew 579 probably reflecting the poorer MDS of the Pixie. I have no idea of his power or antenna.
My initial goals have been met: I built the kit and have managed a QSO on the air with it. With the fatigue associated with my brain bleed still very apparent (I am well and truly shattered currently), I was well pleased. A few more QSOs with the 40m Pixie would be good, HI.
$10 well spent. Excellent little kit. FB little transceiver. Works surprisingly well.
Ham Videos: So far I have only made one?
So far it is the only Amateur Radio video I have made. I find I can write about this stuff, quicker and better than I can make video's. However I have not ruled out future output if I find something decent to record and I have the time to edit the footage.
For now I will leave it to the likes of VK3YE and K7AGE etc, both who output some great "updated" interesting Video's over a wide area of various Ham Radio subjects.
40m Pixie – bench test went well
Well, it took a super-human effort on my part as a result of my extreme fatigue (brain bleed issue) but today I bench tested the little 40m Pixie kit I managed to build earlier this week. It is hard to explain just how exhausting this simple task was for me currently. I now need to recover my energy!
On receive a 1uV signal was perfectly readable and I could detect carrier on/off down to at least below 0.5uV. On TX it was putting out about 250mW into a 50 ohm load. On my antenna it was suffering some AM breakthrough, but less than I was expecting. I was using standard Walkman stereo headphones and a rechargeable 12V sealed lead acid battery. On a small 9V battery I’d expect about 100mW RF out, although this was not tried.
Overall, these results exceeded my expectations: it is more sensitive than I was expecting and the breakthrough of AM broadcasters is certainly OK in the day time. This is of course with no casing at all and no ATU. Using the fitted pot and fitted 1N4001 as a varicap it is easy to get the TX frequency and RX frequency to correspond, often an issue with very simple QRP rigs.
Next stage will be some on-air tests, but it most definitely works. Working the locals should certainly be possible. Sked with G6ALB (3km) arranged for 1000z Sunday on 7.023MHz CW.
UPDATE 2120z: There is a contest in full swing and several Russians and Asiatic Russians copied on the little 40m Pixie. I did not stay on long but there was no apparent BC interference noticeable. So, on a quiet night I should able to use the rig in the evenings. The main issue on RX seems to be the lack of AF filtering, so one has to use “the filter that is between the ears” i.e.the brain.
