[Amps] MLA2500 10 Meter Mod

[Tom W8JI]

> In a message dated 12/17/2006 7:44:47 P.M. Eastern 
> Standard Time,
> bmaser at tampabay.rr.com writes:
>
> have my  MLA2500 up for sale on QTH.com and I received a 
> query as to
> whether the 10  Meter mod had been done.  How do you tell 
> other than trying
> to load  it up on 10?

Bob,

Dentron kind of built to fit the mood of the day and the 
availability of parts. Dentron did a combination of five 
things to prevent 10 meter operation:

1.) They moved the adjustable stop in the bandswitch to 
prevent turning the switch to ten meters.

2.) They did not have a tuned input section installed for 
ten meters in amps that had the ATI-6 (tuned input) board.

3.) Sometimes they left the relay wire to the ATI-6 board 
out.

4.) They left the wire out that goes from the ten meter tap 
on the tank coil to the ten meter terminal of the 
bandswitch.

5.) They installed a trap or lowpass in amps that had 
combinations of the above mods but still failed the 25-30MHz 
gain restrictions for type-acceptance. This was generally 
the higher gain amplifiers using ceramic tubes.

This varied with production runs of the various amplifiers 
as well as the particular model.

73 Tom