Friday, March 17, 2017

Tracking VE3KCL "S22" balloon

At around 1400Z today, Dave VE3KCL launched his 22nd high-altitude balloon from Toronto, Ontario.

The payload for this balloon is based on Hans G0UPL's Ultimate 3S and is transmitting JT9 on 30 meters and WSPR on both 20 and 30 meters into a 2-band vertical weighing 1 gram (probably a dangling wire).

Power output on WSPR is only 20 milliwatts but his antenna is waaaaaay up there.

Thursday, March 16, 2017

A kit in search of a vendor: W8TEE and K2ZIA Antenna Analyzer

Prototype
An upcoming issue of QST will feature an article describing an antenna analyzer designed by W8TEE and K2ZIA.

The $10 circuit board for the kit is already available for sale by QRPGuys here. Additional required parts are estimated to cost about $55.
This Arduino-based analyzer has a color TFT display that presents antenna data either textually or graphically and can save the data to an SD card and present it as an overlay to compare with another trace after an antenna adjustment is made.

The analyzer covers 1.0 to 30.0 MHz and is pre-configured for the ham bands.

Other unique features would seem to make this an ideal kit to be offered by a club since QRPGuys
TFT screen
has no interest in this other than offering the circuit board. The $55 of parts could probably be obtained much less expensively when bought in larger quantities.

Complete build instructions are downloadable here (4MB pdf) and an operation manual is here (2MB pdf).
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Saturday, March 11, 2017

Audio QSLs?

Beginning a few years ago, several contesters - usually Big Gun multi stations - started making searchable audio files of their contacts available so that those they worked during the contest could hear how they sounded on the other end.

A few examples are here:
LN8W (Copied me on 10m CW)
DH8BQA

When I first learned of this, my second thought was that it would be a cool feature to have during DXpeditions. It might increase the appreciation factor for those of us who don't hear the business side of a massive pile-up.

Of Macs and amps...

I said I wouldn't do it - actually pay for a heatsink for my 70-watt amp kit. Any old hunk of metal would suffice to dissipate the heat and surely I'd find a suitable scrap laying around that could be put into service. Well, my garage is neater than I'd imagined - so I bought an Official Heatsink which is now enroute to me.

Once it arrives, I'll drill and tap it, finish the amp and post the results here.

I'm debating how much detail to post regarding the build. There is no documentation whatsoever and there are a few gotchas to putting this thing together. On one hand, I want to help others who want to build this kit (8 of you have emailed me); on the other hand, it's not my job to assist the seller of this amp by doing for free what they ought to be doing themselves. It's a matter of principle...

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A few years ago I had the opportunity to work with a pro photographer - a real one, not a "I'm a photographer with an expensive Nikon, can I photograph your wedding for X dollars?" wannabes that are a dime a dozen. The workflow, from studio lighting to computer processing, was a laborious pressure-cooker for him but a playground for me. He relied on excellent results for his income while I simply wanted to learn.

One thing I learned was that most people in his line of work use Mac computers. So do a lot of others who need to be seen as professionals on the cutting edge.

Last month, I spent many overtime hours working with a couple of engineers on a project to update a Doppler radar system. They used Mac computers to do what I do with a PC - namely, to look at various parameters of the radar using the computer's terminal program. A conversation ensued on the merits of Mac vs. PC and, with the OT providing justification, I bought a used Macbook Pro on eBay.

It arrived in even better than excellent condition, scrubbed of the previous owner's doings and with a fresh install of Sierra. A $300 bargain.

I've always wondered about the PC vs Mac debate and will now be able to see for myself if Macs are really "all that".
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Monday, March 6, 2017

Plans for QRP to the Field 2017

Yours truly during QRPTTF 2004
It's been a long time since I participated in a QRPTTF. In the old days, I packed a 20m DSW, a Norcal 40A and maybe my old Oak Hills OHR-20 for backup. Adding batteries, an antenna, hardware to hold it aloft, a key, headphones and paper log all made for quite a non-portable kit.

Thanks to the KX2 and lessons learned during NPOTA, a lighter and more efficient excursion is now possible. And best of all, no 2-band or CW limitation. From the desktop my KX2 has been giving me the evil eye lately as she sits unused since NPOTA ended and un-adventured since my TAT ride ended.

Sunday, March 5, 2017

Construction of 70-watt eBay HF amplifier - Part 1

I began the "sniff solder" phase of my amp kit today (first described here) and am now at a standstill until I can find something to use as a heatsink. Once I find a suitable chunk of metal I'll have to drill and tap it to accommodate the hardware that will secure the transistors.

Initial assemble was slower than would have been the case with proper instructions and a parts list. Parts are not identified and there are a few ambiguities yet remaining. For example, there is a component on the schematic labeled "C?" with no value indicated. Extra components are included so the C? value cannot be deduced. R7's value is also not indicated.

Saturday, March 4, 2017

Unbuilt ham radio kits as investments?

Unbuilt HW-101
Every now and then I take a look on eBay for my Novice rig. That leads to other views of even more now-rare rigs. Vintage, they call them.

They often command a premium price if they are in excellent condition because the vast majority of already-assembled vintage radios have seen much use, several owners and maybe even some dis-use (storage) and mis-use.

But the rigs commanding the highest prices are unbuilt Heathkit transceiver kits.