[NLRS] EMA-220X mixer??

[Dr. Gerald N. Johnson]

On Tue, 2006-11-14 at 13:36 -0600, Bill K0AWU wrote:
> 
>   Anyone have any information on a EMA-220X mixer that were packed 
> with a 1990 era KK7B transverter instead of SBL-1Xs??
> 
>   They are marked different and I am not sure if they are interchangeable. I 
> have a "pinout" on the SBL-1X but I can find no pinout on the EMA-220X.
> 
>   Maybe the best bet would be finding a couple of SBL-1Xs!
> 
> Bill  K0AWU  EN37ed

My google search showed that the same question was asked on a VHF list
in 2002 and not answered.

I'd think the connection ought to be about the same, else the board
would have to be different and DEM would not have supplied an
alternative without documenting board changes.  You could ask the
present DEMI directly. As I recall, the SBL-1X has a dot above a corner
pin. Some SBL did have a pin with blue glass around it as the corner
marker. Does the EMA-220X blue pin match the SBL-1X dot? Then use your
ohmmeter to see if the transformer and diode connections are in the same
places. While its tempting for a maker to transmute connections to be
unique, its bad business to try to be a substitute source of a product
without matching the main maker's connections.

That transverter was probably shown in a CSVHF or MUD proceedings when
it was new or before it got to production and there might be a mixer
discussion there too. Alternate sources for those unable to get the MCL
products handily.
-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer