[R-390] R390-A problem

[Barry Williams]

Bob,

I'm certainly no expert but could it be the function switch? Mine has 
done the same thing as yours for more than 15 years. I've been too lazy, 
over worked, or unorganized to check it out. Mine will regain audio by 
going to any other switch position most of the time. The off function 
hasn't worked the whole time of this, but it works to get the audio 
strength back.



Barry


> 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
>>>>