[TenTec] Re: Model 253 Autotuner

[Ken Brown]

Peg Haese wrote:

>Chuck, would you or anyone else care to say exactly what 253 tuner
>refinements are necessary? I got one several months ago for the Omni V and
>Herc II but have never hooked it up. I did get a cable from Riley's for the
>trio.
>  
>
The Ten Tec 253 Auto Tuner has only 28 memory tune settings. These are 
arranged as 7 bands X 4 antennas. Depending upon how you choose to 
define the 7 band selections, seven may be enough for you. However, if 
you count all of the present day ham bands (not including the 5 MHz 
channels, they are channels and not a band.) your count will probably be 
greater than seven. Some people have worked around this limitation by 
either using the antenna switch to only select one of four memory banks, 
not using it as an antenna switch at all, or perhaps using it to select 
only two antennas, with 2 X 7 = 14 tune memories for each antenna.

If you interface the 253 to a Ten-Tec Omni or Paragon, for automatic 
band selection, the bands will be: 1.8-2.5, 2.5-4.0, 4.0-6.5, 6.5-12.5, 
12.5-15.0, 15.0-22.5 and 22.5-30.0 MHz. That is only one memorized 
tuning for 160 meters, only one for 80 and 75 meters combined, only one 
for 40 meters and 30 meters combined, only one for 17 meters and 15 
meters combined, and only one for 12 and 10 meters combined. Again, you 
could have as many as 4 memorized tunings for each of the above listed 
"bands" if you give up the antenna switch function, and just use that 
switch for a "memory bank" selector.

I would like to have two or three memories for 160 meters, and two or 
three for 80/75 meters. It would be nice to have two on 40 meters also. 
I would be happy with just one for each of the other bands, as long as 
each band is a separate band, not 17/15 combined or 12/10 combined.

Yes the 253 has an autotune function, so in theory you don't need any 
memories as long as you don't mind waiting for the process to complete 
and enduring the noise of the tuner going through it's paces to get 
tuned. You have to transmit to make the autotune function happen. I 
would like to switch bands, and have the tuner set up for each band, 
without having to transmit. That way I can listen to each band, with the 
antenna system tuned correctly, to decide whether I am interested in the 
way the propagation on a band is at any given time. The 253 can do that 
as long as you choose the seven bands you really want. If Ten-Tec had 
used those seven "band select" lines as seven bit parallel binary, 
instead of only one out of seven select, there could have been 128 
memories  per antenna,(with the right  memory chips in the 253).  Maybe 
the band  frequency divisions could have been entered  through some 
commands in the  "User Options Menu" of the Omni.

DE N6KB