[Fox_Tango] ft-980 master osc problem

[Dr. Gerald N. Johnson]

If you play footsie with the band edge, that's enough error to get you 
in trouble. But since ham frequencies other than 60m are not 
channelized, its not the end of the world. Many a rig struggled to do 
1/10th that good in the past 40 or 50 years.

www.minikits.com.au/electronic-kits/multiplier-kits/Gali-84-30MHz has a 
frequency multiplier kit made to work with an ICOM and a 10 MHz 
frequency standard that should work with the Yaesu as well. There are 
many TCXOs for 10 MHz at Mouser and epay that should have 8 digit 
accuracy and stability and a few that will do a reliable 9 digits, like 
the HP 10811 family, but that takes up space and they have some value. 
They don't do as good as some of the surplus rubidium standards or a 
crystal standard corrected by GPS.

I don't know the oscillator circuit but it might be that the trimmer is 
the least part of the problem, that some fixed capacitor in the circuit 
has drifted or was on the edge of tolerance and that is limiting how 
high the trimmer can move the crystal. More capacitance usually takes a 
crystal down in frequency.

DigiKey has a few thousand 30 Mhz crystals on hand at prices so low you 
can order a couple dozen and pick the one that gets on frequency for 
less than the crystal from Yaesu probably.

Are you sure your counter is good to 8 significant digits? Many without 
super standards like the HP 10811 standard will count 3 to 5 digits more 
than the accuracy of their standard.

73, Jerry, K0CQ

On 1/4/2013 3:51 PM, yash at aol.com wrote:
>                 I have a ft-980 works just fine except the dial readout is off frequency. I put a frequency counter on the board test point an it read 29,999,643, not 30,000,000 as it should. This difference ,is just what the main dial readout is off. There is a adjustment cap on the vfo board to adjust and the 29,999,643 was the highest.  I could get, on the counter. I had a 30,000,000 crystal, I subbed for the original, the reading went up to 29,999,857. . I ordered the new crystal from yaesu,today. I don't know the info on the crystal I subbed,good or bad. I checked voltage feed to the vfo board per the Yaesu manual ,all seemed very close to spec.
>      Anyone have a idea about this, I think the heart of the problem is a bad crystal, would be grateful for any ideas about the problem.
> thanks
> dale wt4t
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