The AM Forum

Does anyone know the input and output frequencies for this converter?  Crystal is stamped 1800 kcs.   I remember years ago IC sold these modules and I think input, mixing, and output freqs were easily changed, but I have no specs or schematics.  I believe this one outputs into a standard broadcast receiver as a tunable IF, but not sure about the RF in.

Thanks in advance for any suggestions....Bill   KL7YB

is this a tube type converter? i have one (International Crystal) with a 6AK5 Rf and 6J6 mixer/osc for 6 meters. uses a 48 MHZ crystal and down converts to 3-6 MHZ. hooked up to a R-390A it just flat blows my ricebox out of the water on 6 meters.

I found this converter for sale but the guy does not have the spec sheet.  He says it uses a 12AT7 and a 6BA6.  Using an 1800 khz crystal, I bet it outputs into the broadcast band, but not sure about the front end frequency.  I might have to just buy the thing and check it with my GDO.  See attached image.

I'm looking for a simple converter like this to build a small 6 metet AM receiver with an old car transistor broadcast band receiver for the tunable IF.  In the mid '60s I built a ten watt 6 meter AM transmitter, 5763 final, from an article in QST, but never built a receiver to finish the mobile project.  Being retired now, I thought I might finish the old project.

Thanks for the reply.

Bill
KL7YB

Bill,

I just found a 1961 International Crystal catalog.  There are several tube and transistor converters.  The best matching converter unit in the catalog is called the FRA-1.  No A20 type of nomenclature was used on the various p.c. board assemblies they offered.

In the attached photo of the FRA-1 assembly, their view is from the opposite side of your photo, but looks like it could be it.  Same tubes as you say, but unfortunately the crystal frequencies are not mentioned.

Your crystal looks like (?)400.000 ?

GL.

Thanks, Tom,
The physical comparisons are very similar.  However, the crystal on the A20 board is stamped 1800 kcs. 

I sent a query to ICMfg Friday and am waiting their reply.  I am hoping they might have some old documentation in their archives.

Thanks to all who replied.

Bill
KL7YB