[R-390] R390-A problem

[Robert Moses]

An insulated stick is also useful for poking around to find parts that 
are cracked or poorly soldered.

Robert Fish wrote:

> Technician in a can!
>
>> It sounds like it's time for freeze spray.
>>
>> Robert Young wrote:
>>
>>> Hello all,
>>>
>>> The radio works normally then after about a ten minute warm up the 
>>> volume jumps up maybe double (normal listing level with local gain 
>>> on 0) and 120 cycle hum is audible. If I click it from AGC to 
>>> standby or AGC to calibrate and back it drops down to normal volume 
>>> again for a few seconds then goes back up, it's almost like 
>>> something is not conducting and needs a little voltage spurt to get 
>>> going again. This was intermittent when it first started a few years 
>>> ago but is now predictable although it was sometimes go back to 
>>> normal by itself. Everything else is the same either way, just the 
>>> volume jumps up (I have to turn down the RF control to get it 
>>> silenced) AGC seems to be working normally. This radio was restored 
>>> by Chuck Ripple about 5 years ago and i have changed some tubes 
>>> since then but have pretty much left it alone besides tubes, it 
>>> works great except for this little annoyance. The power supply was 
>>> solid stated by him. I'm wondering if a cap in the audio chain is on 
>>> it'
>>
>>   s
>>
>>>   way out. I have another audio module but it's inaccessible right 
>>> now. I suspect something in the audio section, anyone have any ideas?
>>>
>>> Bob Young
>>> KB1OKL
>>>                        
>>> ______________________________________________________________
>>> R-390 mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/r-390
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:R-390 at mailman.qth.net
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>>
>>>
>> ______________________________________________________________
>> R-390 mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/r-390
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:R-390 at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>>
>
>
>
>