[Test-Equipment] Millen 9061 GDO with low frequency coils

[Richard Knoppow]

    My Millen GDO is quite accurate. I wonder why yours is not. Might be 
mechanical alignment. I did find the thing is sensitive to the tube 
quality and may not oscillate on the highest frequency coil is the tube 
is weak.
    I agree about coupling, should be the minimum that gives you an 
indication.
    BTW, the meter works as a crystal tester if you make an adapter to 
connect the crystal in place of the coils. The frequency dial will then 
show the optimum capacitance load approximately and will move the 
crystal frequency around a little. A counter or radio receiver is 
necessary to read the frequency.

On 5/8/2024 7:15 AM, k9muf at comcast.net wrote:
> Ray
> 
> If you have an accurately calibrated receiver or a frequency counter, you could very loosely couple it to the GDO. It must be loosely coupled                                  so as not to "pull" the GDO frequency off of it's dip. Also                                             the GDO must be very loosely coupled to the circuit being tested so as to barely get a "dip".
>                                        
> In fact, I use this method for the bands for which the GDO has scales for because those are very hard to read and are not very accurate.
> 
> Don
> 

-- 
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998