RCS 702 80mHz frequency counter - UK Vintage Radio Repair and Restoration Discussion Forum

g0hze snowy · 4th May 2018, 6:20 pm

Hi, has anybody got the schematic for the above frequency counter, I picked one up quite cheaply, having a faulty LED display, cured by cleaning the connecting pins from divider board to display.
My other problem is that any frequency above 7mHz I lose the most significant digit, I found this out during tests by injecting signal from my Marconi 2022e, I injected 14.250 and the display showed just 4.250 and again when I injected 21.050 all I got was 1.050.
Just need to follow the next stage.
Thanks in anticipation
Snowy

Alistair D · 5th May 2018, 12:46 pm

Some of the RCS frequency counters had only 5 or 6 digits and a MHz/kHz switch. The idea is that if the frequency is too high for the kHz position switch to MHz and read the most significant digits then switch back to kHz and add on the least significant ones.

Not sure if the 702 follows this pattern but my old 301 did.

There seems to be nothing on the internet about RCS but I do remember it stood for Radio Component Specialists, a chain of shops from the 70s that supplied components, kits and surplus electronics.

Al

4th May 2018, 6:20 pm	#1
g0hze snowy Hexode Join Date: Oct 2013 Location: Peterborough, Cambridgeshire, UK. Posts: 336	RCS 702 80mHz frequency counter Hi, has anybody got the schematic for the above frequency counter, I picked one up quite cheaply, having a faulty LED display, cured by cleaning the connecting pins from divider board to display. My other problem is that any frequency above 7mHz I lose the most significant digit, I found this out during tests by injecting signal from my Marconi 2022e, I injected 14.250 and the display showed just 4.250 and again when I injected 21.050 all I got was 1.050. Just need to follow the next stage. Thanks in anticipation Snowy

5th May 2018, 12:46 pm	#2
Alistair D Nonode Join Date: Jan 2010 Location: Edinburgh, UK. Posts: 2,008	Re: RCS 702 80mHz frequency counter Some of the RCS frequency counters had only 5 or 6 digits and a MHz/kHz switch. The idea is that if the frequency is too high for the kHz position switch to MHz and read the most significant digits then switch back to kHz and add on the least significant ones. Not sure if the 702 follows this pattern but my old 301 did. There seems to be nothing on the internet about RCS but I do remember it stood for Radio Component Specialists, a chain of shops from the 70s that supplied components, kits and surplus electronics. Al __________________ I won't tell you how I discovered that.