Racal 9916 frequency counter. - UK Vintage Radio Repair and Restoration Discussion Forum

g0hze snowy · 25th Mar 2022, 1:33 pm

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

g0hze snowy · 25th Mar 2022, 2:50 pm

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.

g0hze snowy · 25th Mar 2022, 6:36 pm

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 !!

g0hze snowy · 26th Mar 2022, 10:41 pm

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.

Julesomega · 27th Mar 2022, 1:42 am

Useful and compact 520MHz counter, good to see it resuscitated

25th Mar 2022, 1:33 pm	#1
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 333	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
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 333	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
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 333	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
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 333	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.

27th Mar 2022, 1:42 am	#5
Julesomega Nonode Join Date: Dec 2012 Location: Stockport, Greater Manchester, UK. Posts: 2,102	Re: Racal 9916 frequency counter. Useful and compact 520MHz counter, good to see it resuscitated __________________ - Julian It's good here