[R-390] Question about R-390 Calibration Osc

[Bob Camp]

Hi

Normally 10% low was the design target for this kind of thing. You  
might try simply bumping it up a little. If that's not it then the  
injection level may be low.

Bob

On Jun 6, 2007, at 12:13 AM, Grant Youngman wrote:

>> For the multi-vibrator to work correctly, it needs to be a bit *low*
>> in frequency. It sounds like yours is simply running a bit to high.
>
> I've done some measurements on the thing. When the radio is cold,  
> and the
> multi is apparently NOT syned, it runs at about 85 Khz, which is  
> below the
> trigger frequency.  As the radio warms up, this oscillation rate  
> remains
> very stable. After about 30-40 minutes it goes berzerk (indistinct  
> raspy
> signal as heard in the receiver and unstable trigger on the scope)  
> and then
> restablizes at a clean 100 Khz over about a 2 minute period.  At  
> that point
> it stays put, at least as long as I've been monitoring.
>
> I set the sync adjustment when the radio was hot, which is most  
> likely why
> it pops back into sync when the radio gets hot enough.  I suppose  
> one part
> at a time tested with a heat gun is the next step.
>
> Anyone out there have a surplus cal module for the R-390?
>
> Grant/NQ5T
>