[TenTec] Omni 6 5.5 MHz VFO PLL alignment

Dukes HiFi dukeshifi at comcast.net
Sat Dec 10 22:56:53 EST 2016


First I replaced the PLL chip itself. Then I found an open 10 ohm resistor in the drawing line for the loop IF. I replaced that and also the BF988 IF FET.

I performed a “rough” alignment of that stage to get enough signal through it to get it to lock on most of the band. 

I assume this is a stagger tuned bandpass amplifier with a bandwidth of about 10 MHz, much like a 45 MHz TV set IF back in the day. 

Ideally a sweep generator would be required to properly align such an amplifier. I do have a means to provide a sweep generator of the proper frequency but need to know which of the cans to peak for which portion of the passband. 

Gary


> On Dec 10, 2016, at 1:02 PM, Mike Bryce <prosolar at sssnet.com> wrote:
> 
> wondering what was the repair on the PLL?
> 
> Mike, wb8vge
> 
> 
> Mike, WB8VGE
> SunLight Energy Systems
> The Heathkit Shop
> http://www.theheathkitshop.com/ <http://www.theheathkitshop.com/>
> J e e p
> o|||||||o 
> 
> A man with one clock knows what time it is. A man with two clocks is never sure. 
> 
> 
> 
>> On Dec 10, 2016, at 1:07 PM, Dukes HiFi <dukeshifi at comcast.net> wrote:
>> 
>> Now that I have repaired the PLL on the 5.5 mHz board of this Omni 6+ I am repairing, I need to align the loop IF amplifier and VCO centering.
>> 
>> Is there a resource where I can find this process?
>> 
>> Gary
>> 
>> W0DVN
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