[Amps] Original Ameritron AL-80 question

[ValErwin@aol.com]

In a message dated 1/12/2006 9:08:57 PM Central Standard Time, 
k4nau at comcast.net writes:

> . I don't understand the "wrap around" scale on the Band Switch.  It reads
> 160-80-40-20-15 from left to right, then on the lower scale, it reads
> 24-16-10-6.5 in the opposite direction, ending with the 6.5 between 40 and
> 80????? There are only detents in the switch for the upper bands &the lower
> ones are positioned "in-between" the standard positions

Butch:

The UPPER numbers in the arc are BAND numbers whereas the numbers in the 
lower arc are FREQUENCY numbers.   For example, the amp is capable of operation on 
30 meters as well as in other ham bands. But wait, where is 30 meters?? 30 
meters is the same as 10 MHz in the lower arc. So, you can see if 40 meters is 
appx. 7 MHz and 20 meters is appx. 14 MHz, it only makes sense that 30 meters 
or 10 MHz would be somewhere in between the two!

For sake of conversation/explaination..............

That's right, there is not a detent for 30 M/10MHz (+other HF bands) but you 
can look for a dip in plate current between by either placing the BANDSWITCH 
on 20 or 40 M (try 40M first).

This same logic applies to the PLATE control. Let's say you are trying to 
tune up on 30M / 10 MHz, where would you expect the PLATE control to be when the 
plate current dips?...........between 40M and 20M??...............YES

Trust that explains it for you.............suggest you place the amp on a 
dummy load and "look" for some of the OTHER  "missing" band detent positions and 
then it will start to make more sense to you.

GL and don't let the smoke out !!

Val
W5PUT