Simple AM mod monitor from '47 Sylvania News

[W7TFO]

A simple project for the DIY op.

The parts are still around today.

73DG

[WB6NVH]

I bought the factory made version at a hamfest for $ 3 and I have seen them on eBay for $ 10-15 with no takers, so that option seems occasionally available too.  

Model X-7018

[WA3VJB]

Yeah, this came up on here before.

I have one of them, but never have hooked it up.  $5 hamfest special.

Nice to see the article for the first time. Will print off and motivate myself.

What I need to do is get my local audio on Ch.2 of aircheck recordings.  Ch.1 is the diode output from the receiver, but since I hard-mute to prevent feedback I never had my part on there, not that I care much, but it does provide a complete "take" of the conversation when I send it along somewhere.

The Sylvania box might be the answer, seeing that it's meant to be a transmitter monitor.

[KM1H]

The SB-220 relative power circuit looks a lot simpler, doesnt require tuning, and is sensitive enough for a good exciter...or can be modified for lower power.
Then just add the AF parts.

I never cared for the add a link approach.

Another circuit is the old Heath/Knight SWR bridge, just add the AF part

Carl

[Steve - K4HX]

Yep. Get a Rad Shack or similar cheapie SWR/FS meter at a fest for less than $5 and add a hi-Z audio amp and you're set.

[Opcom]

The meters off old junk CB modulation meters would be perfect for this project.

[kg8lb]

 Thanks for the info. A nice, authentic vintage style meter