SPECTRA A9 HEAD CHANGE

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STEVE W
Posts: 172
Joined: Mon Sep 03, 2001 4:00 pm

SPECTRA A9 HEAD CHANGE

Post by STEVE W »

This question may have been asked before, but what will happen if I put an A7 head on a mid power A9 Spectra to convert it to dash mount and for testing without hacking the programming or is it just a simple change?
Thanks
Steve
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txshooter
Posts: 881
Joined: Mon Apr 15, 2002 7:15 am

Re: SPECTRA A9 HEAD CHANGE

Post by txshooter »

Search and you will find.....

Here is the definitive page on Spectra's....

http://www.open.org/blenderm/spectra/index.html

And for thoise who tend to forget http://www.batlabs.comis still up with lots of information as well!!!

And no it is not just a simple head change!
Scott B.
"Never argue with seven men when you are carrying a six shooter..."
Mike B
Posts: 907
Joined: Thu Sep 20, 2001 4:00 pm

Re: SPECTRA A9 HEAD CHANGE

Post by Mike B »

The problem is the A9 head stores the mode names inside the control head. So, the radio drawer tells the head to display a numeric mode number 1, 2, 3, or 4, etc. The radio to control head communication is a simple mode number. The head translates the mode number into the alphanumeric name for the display.

With the A7 head, the radio stores the mode names inside the radio drawer. So, the radio drawer tells the head to display an alphanumeric mode name "ROCKY", "TAC", etc. The radio to control head communication is a more complex string of characters that are the actual mode name. This control head does not know anything about mode numbers.

If you connect an A7 head to a radio drawer that thinks it is supposed to be talking to an A9 head, the A7 head does not know what to do with the mode numbers and the display will not work.

If you connect an A9 head to a radio drawer that thinks it is supposed to be talking to an A7 head, the A9 head does not know what to do with the mode name characters and the display will not work.

If your Spectra RSS lets you change the "S9000E" control head type to "standard", then you can use the A7. However, "standard" on the Spectra will be either an A5 or an A7 depending on the Moflags (I would expect an A7 from an A9 drawer). Anyway, your keypad on the right of the display may only work like an A5 depending on the Moflags in the radio drawer code plug.
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