With the cooler weather finally upon us I've had time to turn my attention to the Red Hot 20 project. I'm coming up on the 50% completion point and am currently working on the receiver section. The VFO, Audio Frequency Annunciator (AFA), and keyer have been assembled and function tested; happily the magic smoke stayed in all the components on power up.
For all those who may not be familiar with the dark arts as relates to electronics, all these devices run on magic smoke and when you do something to cause the release of said magic smoke the device will no longer function. ;-)
One of the really nice things about this kit is the way the designer, Dave Fifield AD6A, thought about the builder. The radio goes together in stages with power-up and performance checks along the way so there are no surprises when the rig is finished, you know it will work. I had a small solder bridge on the pads of the switch that controls the keyer which caused it to stay in command mode and I was easily able to find the problem and fix it because there were so few components on the board, it made troubleshooting a breeze.
When I get to the receiver alignment portion of assembly, I intend to produce a YouTube video of the procedure to aid others who might be building this rig or happened to acquire an already built one. I'm going to use an audio spectrum analyser program on my Mac to set the BFO sideband and check the filter shape. I learned this technique building several Elecraft K2s and once you understand the concept it works very, very well. Unfortunately I don't currently own a calibrated signal generator, it would be nice to check to see if the Minimum Discernable Signal (MDS) in my built unit is as good as the radio's specification (-135 dbm which puts this rig's receiver in the same class as an Elecraft K2).
One great piece of news, Doug Hendricks KI6DS, proprietor of Hendricks QRP Kits has purchased the assets of Red Hot Radio:
December 1, 2011I am pleased to announce that Hendricks QRPKits has purchased Red Hot Radio Company, owned by David Fifield, AD6A. With this purchase, I now have the exclusive rights to produce and sell all of the Red Hot Radio Kits, including the Red Hot 40, the Red Hot 20, and the SMK-1. Red Hot Radio produced some of the highest quality kits for several years, but was closed due to Dave not having the time to run the company because of his day job. Now, those kits will again be available. The first kit that I will bring back online is the Red Hot 40, and it is available for shipping now. There are 35 kits in the first run, all on 40 meters. The next kit will be the SMK-1 which will be available in about a month. I encourage you to go to the website, www.qrpkits.com and check out the manual for the Red Hot 40. The kit will sell for $250 plus shipping and handling. And the kit is in stock and available for immediate shipping.
If I can manage my time well, there is a possibility that the Red Hot 20 will be completed in time for the G-QRP club's "Winter Sports" activity. It's a non-contest that runs from Christmas to New Years to encourage QRP ops to get on the air; with the current level of sunspot activity working Europe on 20 meters QRP should be easily achievable.