Well,
My TEAS (Test Equipment Acquisition Syndrome) condition seems to worsen; I have acquired another Nixie frequency counter from that great auction site.
I've fiddled around with it considerably to get the internal clock to stabilise - some bright spark, maybe even the designer, has stuck a block of polystyrene (Styrofoam) over the crystal to try and maintain some temperature stability - but alas its all over the shop.
So, I've basically hacked two holes into the back of the unit and added an external reference clock input - this can be supplied by my ever faithful shack frequency reference.
So this is the unit; albeit on its side:
And here the small modification I've made:
The circuit forces whatever signal is on the input to be +ve DC - I've built it dead bug style on the back of the input BNC socket:
This is where I was poking about to find the clock output:
Using some of my other ancient test gear acquired through my TEAS condition:
Here's the result:
Lovely Jubbly.
My TEAS (Test Equipment Acquisition Syndrome) condition seems to worsen; I have acquired another Nixie frequency counter from that great auction site.
I've fiddled around with it considerably to get the internal clock to stabilise - some bright spark, maybe even the designer, has stuck a block of polystyrene (Styrofoam) over the crystal to try and maintain some temperature stability - but alas its all over the shop.
So, I've basically hacked two holes into the back of the unit and added an external reference clock input - this can be supplied by my ever faithful shack frequency reference.
So this is the unit; albeit on its side:
And here the small modification I've made:
The circuit forces whatever signal is on the input to be +ve DC - I've built it dead bug style on the back of the input BNC socket:
This is where I was poking about to find the clock output:
Using some of my other ancient test gear acquired through my TEAS condition:
Here's the result:
Lovely Jubbly.
RCS were based in Teddington and they also manufactured a standard frequency receiver locked to 200kHz (probably for this very counter). Come the day Droitwich shifted from 200 to 198kHz, everything else locked to it in the workshop moved in sympathy.
ReplyDeleteId love to find a schematic, but I cant find anything relevant on the internet at all :-(
DeleteI too have TEAS! Now I know it has a name! I have a RCS type 501T which is similar in looks to yours and has a timer function. I am not sure how the timer function works, there are 'start' and 'stop' bnc inputs which I have traced back to the clock inputs of a 7474 D flip flop via a limiting resistor and 4V7 zener. Any circuit diagrams or user manuals would be a help. Have you had any experience with the timer function? Regards, PT
ReplyDeleteI dont have any experience but my guess would be that an external signal can start and stop the counter for timing or other purposes.
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