This is a vintage used Belar Electronics Laboratory, Inc. AMM-1 AM Modulation Monitor. The power cord is missing so I have not powered it up. Power cord connection to unit is a bit different design. I tested the meters and all three deflect when tested for resistance; Modulation meter has 1170 ohms resistance, % Carrier meter has 120 ohms resistance (dial cover has crack in middle), and HZ Deviation has 130 ohms resistance.

It was in a large amount of equipment from a working AM radio station that closed down recently when it was purchased and converted to FM. I acquired the equipment and will be selling in the next few months, so be sure to bookmark in Favorite Sellers.

I have no manual and no way to drive it with a signal, so no further testing was done. Belar is still in business and they have manuals for models with similar features, perhaps they can make a manual for this available. The Belar web site is at /

A visual inspection shows that it is pretty complicated, but I see no obvious damage. It may have been in use when the station was shut down, as the only other monitors were early Gates units (those are already sold). Not sure what the value might be, so feel free to make an offer.

US only, no International sales. It weighs 14 lbs,

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