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Title: S-meter Post by: W1RKW on January 30, 2011, 04:18:27 PM I have a Retro-75. It want to install an S-meter so I was thinking of taking the 6 MHZ IF and making an attempt at installing a homebrew S-meter. I 'm not looking for accuracy but just relative signal strength and something to look at beside the LED I have with my Retro. So the question is, how should I approach this? I'm thinking of some sort of buffer to pick off the IF signal so as to not load the IF section down then rectify signal and filter it to a DC voltage and feed it to a meter. Any thoughts suggestions?
For those interested in the receive section schematic of the Retro75 see page 9 at link below: http://smallwonderlabs.com/Retro-75_Instr.pdf Title: Re: S-meter Post by: KA8WTK on January 30, 2011, 04:32:59 PM Page 5 mentions D6 which supplies an AGC voltage to Q4. You might try measuring the voltage that the diode supplies to Q4. That might be what you are after.
Bill Title: Re: S-meter Post by: Knightt150 on January 30, 2011, 05:28:48 PM If anyone comes up with a S meter and power output combination and loading controle for a RETRO-75 please let me know. I have a HW 8 case I would like to install all this in. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
John W9BFO |