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Got the frequency counter aligned

Posted: January 17th, 2022, 12:02 am
by MN785
I had bought an FC-7015U 150MHz counter off ebay a few years back and tonight I finally got it aligned. What I thought would be a 20 minute project turned out to be 3 hours. I couldn't get the 10MHz WWV signal, but the 5MHz one was in there, so I connected a signal generator to the FC and a makeshift antenna and adjusted the SG till the beat in the radio was less than one every 10 seconds. After the first hour chasing WWV with a cold SG, and with a billion tries with the plastic screwdriver blowing past the mark every time once that had warmed up, I finally landed it where it needs to be. The display said 5.000 000 when zero beat to WWV. I assumed they would have used a smaller variable cap in that little tin can oscillator to make that job easier, not my luck. Anyhow, I celebrated the occasion by removing the screen protector film on the FC and promised myself I'd never again punch my desk again when a project **Censored** me off :)

Re: Got the frequency counter aligned

Posted: April 3rd, 2022, 5:54 pm
by TrapperDave
Congrats! My next project is an RCI 2950 cap swap. I hope it helps the old girl!

Re: Got the frequency counter aligned

Posted: April 4th, 2022, 9:22 am
by MDYoungblood
MN785 wrote: January 17th, 2022, 12:02 am I had bought an FC-7015U 150MHz counter off ebay a few years back and tonight I finally got it aligned. What I thought would be a 20 minute project turned out to be 3 hours. I couldn't get the 10MHz WWV signal, but the 5MHz one was in there, so I connected a signal generator to the FC and a makeshift antenna and adjusted the SG till the beat in the radio was less than one every 10 seconds. After the first hour chasing WWV with a cold SG, and with a billion tries with the plastic screwdriver blowing past the mark every time once that had warmed up, I finally landed it where it needs to be. The display said 5.000 000 when zero beat to WWV. I assumed they would have used a smaller variable cap in that little tin can oscillator to make that job easier, not my luck. Anyhow, I celebrated the occasion by removing the screen protector film on the FC and promised myself I'd never again punch my desk again when a project **Censored** me off :)
I bought one similar, the adjustment was so touchy, aligning it was very frustrating. I looked at it for a while and thought if I changed the value of a resistor at the potentiometer sweep it became less sensitive. It's been on my bench up until my move.

3's

Greg