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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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25th Mar 2022, 1:33 pm | #1 |
Hexode
Join Date: Oct 2013
Location: Peterborough, Cambridgeshire, UK.
Posts: 336
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Racal 9916 frequency counter.
just received a 9916 counter, 1st obvious damage inside when i looked was the battery tray was rusted and minor marks on the PCB, only 50% of the individual 7 seg displays lite up , sections a,c,d,e, that turned out to be dirty connector, a clean with detoxit and those horrible fiber glass pens corrected that.
i injected a 45mHz signal into the 'B' input and it was correct to within a few hertz, when i injected a 145.5mHz into the 'A' input it was reading just 291mHz, now i have heard that the relay can give problems, 'Is this one of them' if not then i will look further. regards |
25th Mar 2022, 2:50 pm | #2 |
Hexode
Join Date: Oct 2013
Location: Peterborough, Cambridgeshire, UK.
Posts: 336
|
Re: Racal 9916 frequency counter.
forgot to add, random counting in position 'A' with no input, ok on position B.
Just realized that the output shown on 'A' is double the input frequency, Some voltages taken from IC29, pin 1,4 and 5 at -8.9v, pin 3 is 2.79v,pin 6 -5.4v Q52 (MJE520) has -9.10v on pin 8 and -9.08v on pin 9, this is supposed to be -5v rail. |
25th Mar 2022, 6:36 pm | #3 |
Hexode
Join Date: Oct 2013
Location: Peterborough, Cambridgeshire, UK.
Posts: 336
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Re: Racal 9916 frequency counter.
well that all sorted, changes 3 x blue tants, C's 83,86,88 and Q34 ztx550, frequency display settled down immediately and followed input frequencies from my 2022.
Got to change I/C,s 19,22 due to corrosion on their legs, don't anticipate any problems but !! |
26th Mar 2022, 10:41 pm | #4 |
Hexode
Join Date: Oct 2013
Location: Peterborough, Cambridgeshire, UK.
Posts: 336
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Re: Racal 9916 frequency counter.
IC's changed, been on soak test with different 'f' inputted from my 2022 for 2 hours, all sorted, now in service and replaced my other 9916, now to continue with the 9009, sorry about the mistake in the 'for sale' column, the moderator has altered it for me, many thanks for that, put it down to the grey cell being tired.
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27th Mar 2022, 1:42 am | #5 |
Nonode
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,106
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Re: Racal 9916 frequency counter.
Useful and compact 520MHz counter, good to see it resuscitated
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