[Tgace459]

So...I just recapped a Hallicrafters 5R42. It was going GREAT. Played and tuned in stations like a champ.

Until I left it playing on my workbench for a while. After about 30 min it drifted out of tune and went to static.

After poking around I noticed that as I tuned it I could get reception momentarily if I kept some turning pressure on the knob so I focused on the tuning cap. I can hold a station by adjusting the cap padder. But the moment I tune off of that station I can maybe get 1 or 2 other stations, but poorlyand, I loose the previously strong station when I tune back to it again.

It also went from being a strong receiver with its ferrite rod antenna to only being strong if I happen to touch the antenna or the cap.

Can anyone give me some suggestions?

[Radioroslyn]

http://gmcotton.com/ham_radio/misc%20man...Manual.pdf

Is the loop connected??? Both ends?? Clean the band switch.  Try another 1R5. You know the drill start checking voltages around the 1R5. On these portable sets filament voltage is somewhat critical, if low can create problems.

[Tgace459]

Thanks. Another thing I noticed this morning before I left for work is that after sitting to cool overnight it went back to "good". Something to do with heat?

[Radioroslyn]

Possible but as you might have noticed that the set doesn't get very hot. I would try swapping the tubes and checking the voltage at R-14 where it connects the AC/Battery switch. Should have about 7.5vdc. Check when set is not working properly. It's about the only thing that gets hot short of the filaments.

[Tgace459]

Hmmm...still misbehaving.

The set will work perfectly on start up for maybe 15-20 minutes and even longer if I don't adjust the dial. What I have found is that when I go around the dial and pass the 700-750 kHz part of the band I get a noticeable spike of staic/noise then no station tunes in. If I tune to a strong station and adjust (sometimes just tap on..) the padder it will "pop" back in and seem fine again but then go spotty on its ability to get other stations strongly.

I've cleaned the paddlers and replaced the adjustment screws and on a few occasions thought I had it licked. But no.

I know previous advice was to check the tubes but I sure seems like there is something up with the tuning cap area of this radio....

[KCMike]

Have you by chance checked the tuning capacitor plates to make sure there isn't some contact (plates rubbing)?

[Tgace459]

Have you by chance checked the tuning capacitor plates to make sure there isn't some contact (plates rubbing)?

I suppose it's possible, but I can't tell by sight.

[gregb]

I just finished one of these radios and I had the exact same problems, it sure seemed like the tuning cap was rubbing. It ended being the 1R5 tube socket was causing some kind of a problem. I tried cleaning it with a slight improvement but it did not fix the problem. I found that if I pushed down on the tube with a bit of pressure it would work fine. So I ended up replacing the socket and it works perfectly now. I examined the old socket under a magnifying glass and could not see any problem but the replacement works perfectly. This may not be your problem at all but it fixed mine.

Gregb