12-01-2016, 04:42 PM
This counter module was brought to my attention in this thread:
http://philcoradio.com/phorum/showthread.php?tid=15414
Terry mentioned that they were selling for around $9 on ebay and I became interested and ordered one.
Well it arrived today and proceeded to try it out.
Must say that I am quite impressed. Reads dead on in frequency up to 70 Mhz or so and sensitivity is very good. In the photo it is reading a 7 Mhz signal at a level of only 10 millivolts.
It also uses very little power. I measured only 25 mA at 9VDC supply.
One of these counters could be incorporated into an inexpensive vintage signal generator for less than $10.
It really does not need an external supply, as all that would be needed is a diode and filter cap connected to the 6.3VAC filament winding to supply around 9 VDC for the counter. The counter input could be connected through a small value (470 pF) cap and series resistor directly to the signal output before the attenuator. That way, no matter what the output setting, the counter would always read the full level signal.
The module is tiny and it could be built right into the generator box, or if you didn't want to modify it you could mount it in a small case and put it on top.
[img]IMG_2779.JPG[img/]
http://philcoradio.com/phorum/showthread.php?tid=15414
Terry mentioned that they were selling for around $9 on ebay and I became interested and ordered one.
Well it arrived today and proceeded to try it out.
Must say that I am quite impressed. Reads dead on in frequency up to 70 Mhz or so and sensitivity is very good. In the photo it is reading a 7 Mhz signal at a level of only 10 millivolts.
It also uses very little power. I measured only 25 mA at 9VDC supply.
One of these counters could be incorporated into an inexpensive vintage signal generator for less than $10.
It really does not need an external supply, as all that would be needed is a diode and filter cap connected to the 6.3VAC filament winding to supply around 9 VDC for the counter. The counter input could be connected through a small value (470 pF) cap and series resistor directly to the signal output before the attenuator. That way, no matter what the output setting, the counter would always read the full level signal.
The module is tiny and it could be built right into the generator box, or if you didn't want to modify it you could mount it in a small case and put it on top.
[img]IMG_2779.JPG[img/]
