1969 Advert

[Anonymous]

Rummaging around in the loft and came across my first advert in the November 1969 Coins Weekly. Detector ran at 22 pulses per sec with sample delay of 75uS. Good ranges on copper and silver coins but not so good on cupro-nickel. Wonder if any of these units still exist.
Eric.

 

[Anonymous]

Great advert Eric! I would have bought one myself at that time I believe. Did you write the text for the ad? There are pulse units today that don't get 14" on a US penny. I enjoy seeing old ads and such like these-keep them coming from time to time.
James

 

[Anonymous]

Hi James,
Yes, I did the text and layout. Not bad for a first attempt. Haven't improved since, though. I was wondering about the claim I made that you could operate in all sorts of interference; then I remembered that the detector had a very slow response time (long integrator time constant) that would average out most noise. The slow response was OK because you could not sweep a 9lb detector fast anyway, even though it was balanced about the carrying point. Receiver used a 709 front end, 702's for the differential integrator and dc amplifier. Timing logic was Fairchild RTL and transmitter switch BUY12.
Eric
Eric.