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g0hze snowy · 25th Nov 2020, 3:10 pm

Good Afternoon Gents, right got my head in gear and had another go at the 9916 today. results as follows:
TRH01uk, i have 4.98v to each of the driver trannies, your suggestion was to check IC1 pin 4, its at 3.314v, your other suggestion checks out ok q1-Q5 appear ok.
MotorBikeLes, no sign of any burn marks or tants without hats.
Peterg0rsq. the checks you asked me to do have the following results:
Q1 to 4 and 6 yes
Q5 ? is that IC4 pin 11?
Q7 there is a 'sort' of waveform but it looks like mush compared to all the others i have checked out.
Q8 yes
The only front panel LED,s that are on are mHz, gate/charging and the decimal point which changes with the operation of the front panel switch.
now sorry but i forgot to include the author of the next set of observations but the results are as follows:
he suggests i probe IC1, multiplexed pulses on pins 1,2,6,7.
status of Blanking input pin 4, no signal but showing 12mv saw tooth type wave form
lamp test pin 3, changes state when test button pressed h/l.
Pin 8 shows 4.26v with respect to chassis, pin 16 show 4.18v with respect to 5v line.
now onto IC,s 23 and 28, i have pulses on pin 14 and a,b,c,d pins 1,2,8,9, pins 2 and 3 are at 0.106v
Ic28 is the same as IC23
Tants changed on switching trannies but no change, so they were probably ok.
finally just a list of the voltages on the test points:
TP2 23.45V ( SHOULD BE 24V)
TP3 4.91V
TP4 5.02V
TP5 GROUND
TP6 -4.2V
Here endeth todays observations
over to you gents..

25th Nov 2020, 3:10 pm	#20
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 339	Re: Racal Dana 9916 Frequency Counter. Good Afternoon Gents, right got my head in gear and had another go at the 9916 today. results as follows: TRH01uk, i have 4.98v to each of the driver trannies, your suggestion was to check IC1 pin 4, its at 3.314v, your other suggestion checks out ok q1-Q5 appear ok. MotorBikeLes, no sign of any burn marks or tants without hats. Peterg0rsq. the checks you asked me to do have the following results: Q1 to 4 and 6 yes Q5 ? is that IC4 pin 11? Q7 there is a 'sort' of waveform but it looks like mush compared to all the others i have checked out. Q8 yes The only front panel LED,s that are on are mHz, gate/charging and the decimal point which changes with the operation of the front panel switch. now sorry but i forgot to include the author of the next set of observations but the results are as follows: he suggests i probe IC1, multiplexed pulses on pins 1,2,6,7. status of Blanking input pin 4, no signal but showing 12mv saw tooth type wave form lamp test pin 3, changes state when test button pressed h/l. Pin 8 shows 4.26v with respect to chassis, pin 16 show 4.18v with respect to 5v line. now onto IC,s 23 and 28, i have pulses on pin 14 and a,b,c,d pins 1,2,8,9, pins 2 and 3 are at 0.106v Ic28 is the same as IC23 Tants changed on switching trannies but no change, so they were probably ok. finally just a list of the voltages on the test points: TP2 23.45V ( SHOULD BE 24V) TP3 4.91V TP4 5.02V TP5 GROUND TP6 -4.2V Here endeth todays observations over to you gents..