No reception between 800 and 1200 KHz. - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

capbuster · 25th Apr 2010, 6:41 pm

Yes . works all over for 20 minutes . Then nothing no hum ,static , quiet. from 800 to 1200.
Thanks .

PJL · 25th Apr 2010, 7:23 pm

I understand it goes quiet from 800 to 1200 after 20 minutes. I am asking if it makes any noise below 800 and above 1200?

The voltages on the circuit can't be trusted. The screen grid voltages vary from 62-82V and they are all connected together!

Try measuring the anode voltage of the oscillator (27) with a DMM when it has just warmed up and again when it has stopped working.

capbuster · 25th Apr 2010, 8:01 pm

Yes it does . Works all over the dial for 20 minutes then from 800 and in between 1200 . Nothing quiet no static nothing . Let cool down then plays good again.
Thanks.

capbuster · 25th Apr 2010, 8:05 pm

Sorry for the double post . didnt show up till i posted again. NO NOISE AT ALL.
Will check thank you.

PJL · 25th Apr 2010, 9:29 pm

Measure the voltage I suggested. The HT may be falling away.

capbuster · 26th Apr 2010, 8:16 pm

Ok checked it is 60 volts . On this set i have to take chassi out .
Turn it up on it,s side take bottom cover off . Then plug speaker in.
Never check this set out with speaker unplugged . Strange thing been playing for two hours without cutting out . But still quiet 800 to 1200 nothing .
Picks up great 800 to 500 & 1200 to 1555. Checked all other plate voltages out checked in specs. Dont know

Thanks Capbuster.
Going to check for loose wire playing great on it,s side.

25th Apr 2010, 6:41 pm	#21
capbuster Retired Dormant Member Join Date: Mar 2010 Location: Bristol, Virginia, USA. Posts: 31	Re: No reception between 800 and 1200 KHz. Yes . works all over for 20 minutes . Then nothing no hum ,static , quiet. from 800 to 1200. Thanks .

25th Apr 2010, 7:23 pm	#22
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: No reception between 800 and 1200 KHz. I understand it goes quiet from 800 to 1200 after 20 minutes. I am asking if it makes any noise below 800 and above 1200? The voltages on the circuit can't be trusted. The screen grid voltages vary from 62-82V and they are all connected together! Try measuring the anode voltage of the oscillator (27) with a DMM when it has just warmed up and again when it has stopped working.

25th Apr 2010, 8:01 pm	#23
capbuster Retired Dormant Member Join Date: Mar 2010 Location: Bristol, Virginia, USA. Posts: 31	Re: No reception between 800 and 1200 KHz. Yes it does . Works all over the dial for 20 minutes then from 800 and in between 1200 . Nothing quiet no static nothing . Let cool down then plays good again. Thanks.

25th Apr 2010, 8:05 pm	#24
capbuster Retired Dormant Member Join Date: Mar 2010 Location: Bristol, Virginia, USA. Posts: 31	Re: No reception between 800 and 1200 KHz. Sorry for the double post . didnt show up till i posted again. NO NOISE AT ALL. Will check thank you.

25th Apr 2010, 9:29 pm	#25
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: No reception between 800 and 1200 KHz. Measure the voltage I suggested. The HT may be falling away.

26th Apr 2010, 8:16 pm	#26
capbuster Retired Dormant Member Join Date: Mar 2010 Location: Bristol, Virginia, USA. Posts: 31	Re: No reception between 800 and 1200 KHz. Ok checked it is 60 volts . On this set i have to take chassi out . Turn it up on it,s side take bottom cover off . Then plug speaker in. Never check this set out with speaker unplugged . Strange thing been playing for two hours without cutting out . But still quiet 800 to 1200 nothing . Picks up great 800 to 500 & 1200 to 1555. Checked all other plate voltages out checked in specs. Dont know Thanks Capbuster. Going to check for loose wire playing great on it,s side.