Alan, Thanks. Looks like I might do some experimenting later but probably won't have the time until Summer.
73, phil, K7PEH On Feb 9, 2012, at 10:11 PM, Alan Bloom wrote: > I downloaded the HQ-170A schematic and took a look at the schematic. It > looks like the 455 kc output is taken directly from the plate of the > second mixer through a 10 pF (oops, I mean 10 mmF :=) capacitor. > > Since 10 pF has 35 kohms reactance at 455 kHz, you'll probably need a > buffer to drive the P3's 50-ohm input. You could use a cathode follower > (if you want to be authentic) or an FET source follower (with clamp > diodes at the input to protect the gate from voltage transients). > > Let us know how it turns out. > > Alan N1AL > > > On Thu, 2012-02-09 at 21:03 -0800, Phil Hystad wrote: >> So, I get my Hammarlund HQ-170A out of the storage garage because I >> got a re-tubing kit and I am finally going to replace some or all of >> the tubes. The HQ-170A works but audio is a little on the weak side >> and sensitivity could be improved. I will do the tube thing first and >> then maybe consider some alignment experiments. >> >> But... >> >> I noticed on the back, something I have never noticed before that I >> remember, is that there is a 455 KC (well, it says KC) IF output. I >> am guessing I might be able to plug this into the P3. >> >> Am I guessing right or is there some other stuff I might have to >> consider -- such as signal level (voltage) or other things. >> I don't suppose anyone out there in Elecraft-land has hooked their >> HQ-170A receiver up to the P3. If so, let me know how it works. >> >> 73, phil, K7PEH >> > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
