The receiver is mostly done on my 15-10 rig, and I am following Farhan's BITX20 advice: "pause at this point and listen to the receiver that you have built."
In the video I mention a problem with out-of-band signals. I was hearing shortwave broadcast signals (Brother Stair!) and even strong 20 meter CW signals. I thought the problem may have been with the bandpass filters, but after thinking about it I focused on the diplexer coming out of the product detector. I put a simple diplexer (from W7EL's Optimized Transceiver) in there and the problem disappeared. I still plan on beefing up the Bandpass Filters -- the dual tuned circuits I have been using are, I think, inadequate. I needed some more space on the wood board so I installed a sort of "back porch" -- you can see it in the video. I will build a power amplifier (RD6 or RD16) and a mic amp. Soon I will be on 15 and 10 with this rig. On this one, I am going the full "radical fundamentalist homebrewer" route: no ICs, no manufactured PC boards, no VFOs from old Yaesus.
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41 minutes ago
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ReplyDeleteI committed the ultimate degradation of a QF-1 variable cap, yanked some plates - bad idea.
ReplyDeleteI used the QF-1 enclosure for an audio signal generator - a project from the first issue of Ham Radio Horizons.
Best Regards,
Chuck, WB9KZY
Been there, done that Chuck. A youthful indiscretion I'm sure. At least you made good use of the enclosure. But now there are at least THREE QF-1 killers out there. You, me and Dean KK4DAS. SOMEBODY STOP US!
ReplyDeleteI guess there is also the HD-11 which looks similar to the QF-1 but the HD-11 has a built-in power supply. AND there is the GD-125 which has a lower profile. So lots of Heathkit Q-multipliers out there ready to be messed with by modern marauders !
DeleteI wish I could sign in, the HD-11 comment above was from me, Chuck, WB9KZY.
DeleteBTW, my QF-1 was given to me by one of my Elmers, he didn't care what happened to it :)
Sure Chuck. That's what they all say. Also: "It was in such poor condition, that it had no historical value." YOU ARE RATIONALIZING!
ReplyDeleteNo doubt you are right, I find the BLS inflation calculator an enabler of rationalization when buying old junk on ebay.
DeleteBTW, I looked at my QF-1 (the audio oscillator) - I had used a bunch of Sprague Vitamin Q capacitors - our fellow travelers in homebrew, musicians, apparently go nuts for these old, hermetically sealed caps !
Best Regards,
Chuck, WB9KZY