04-26-2006, 10:10 PM
Hi All
The 37-650 decided to start getting intermittent, RF gain would just nose-dive. This turned out to be a defective 6K7G IF tube.
After I replaced the tube, I was greeted with a pleasant bonus.....less hum!
It still has just a little hum, which all my radios do. I'd call it normal. 
The 6K7G was an original, that checked on the low side of "good" on my Jackson 648A. I figured it had a HK short, but I could only get the short indicator neon to flicker......with 7.5 VAC on the filament. No shorts with 6.3 applied.
Odd that an IF tube would increase hum with the volume control turned all the way down.
Ever heard of such a thing?
Thanks,
Ed
The 37-650 decided to start getting intermittent, RF gain would just nose-dive. This turned out to be a defective 6K7G IF tube.
After I replaced the tube, I was greeted with a pleasant bonus.....less hum!
It still has just a little hum, which all my radios do. I'd call it normal. The 6K7G was an original, that checked on the low side of "good" on my Jackson 648A. I figured it had a HK short, but I could only get the short indicator neon to flicker......with 7.5 VAC on the filament. No shorts with 6.3 applied.
Odd that an IF tube would increase hum with the volume control turned all the way down.
Ever heard of such a thing?
Thanks,
Ed
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
