I'm making slow but steady progress on this one. The origin of the project was the beautiful National HRO dial and gearbox that Armand WA1UQO gave me. I decided to use a 455 kHz IF because; 1) That was the IF of the old HRO receivers (the ones that won WWII) 2) I had a nice TOYO CM455 crystal mechanical filter that would be good for SSB. 3) I figured it would be easy to add in a wider filter that would be good for AM shortwave listening. 4) I like to keep the IF below the frequency of the VFO. The wide filter turned out to be harder than I thought, but I think I have finally achieved the selectivity I was looking for.I'll have a switch on the front panel that will allow me to go from "AM-Wide" to "SSB Narrow." The switch will change the filters and the detectors, and will turn the BFO on and off.
Still to do: I need a high-pass filter to knock down RFI from nearby AM broadcast transmitter. And an RF gain control would be nice.
I'm really glad Radio New Zealand is there. It provides welcome relief from the shortwave fire and brimstone. Radio Romania is also doing a fine job on shortwave.
In response to popular demand, "SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
For the print version:
For shipping from a printer in the U.S. (probably better for N. American buyers) Click here: SolderSmoke USA Version
For shipping from a printer in the UK, Spain, or the USA (probably better for UK and other European buyers)
Click here: SolderSmoke EU Version
The two versions are identical, except for a minor difference in the paper used. That's why the prices are a bit different.
Bill's OTHER Book (Warning: Not About Radio)
Click on the image to learn more
W4HBK's QRSS Grabber: The Amazing Pensacola Snapper (Live!)