Spectra A9 to A7

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kcbooboo
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Spectra A9 to A7

Post by kcbooboo »

I have a UHF Spectra D44, radio only. The model number indicates it originally had an A9 head. I put an A7 head on it and at least it powers up, beeps, passes self-test, and transmits. Next step is to read the codeplug.

The radio starts transferring data, then I get an error saying it can't find the S9000 head. I don't have one. If I did, I could put it on, change the head type to A7, reprogram the radio, and put the A7 head on.

I believe I can bit-bang the head type in the command board and the MLM to change it from A9 to A7. Is that all that's required, or is there a better, more foolproof way? Once I read the codeplug, I can change things properly, but right now I'm stuck.

Thanks.

Bob M.
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JAYMZ
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Post by JAYMZ »

Since channel names on the spectra are stored in the control head the write and read process will look for acknowledgement from the control head to continue.

If you are going to use the A7 control head you can jumper pins 20 and 22 on the DB25 connector to power the radio and get into the service aids menu. From there you change the head type and model number for the A7 and it'll read and write for you all day long.
JAYMZ

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kcbooboo
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Post by kcbooboo »

Thanks, but I may have gotten one step ahead of you. I pulled the trunk-mount front panel (two DB25 jacks) and plugged my A7 head into the radio; that's how it's configured right now. I can get into the service modes on the front panel, and I can also get into them via RSS through the DB15 jack in the back. There are 9 modes already programmed into the radio, and I can cycle through them with the MODE button.

If I bit-bang the control head byte at 6060 to tell it I have an A7 head, I suppose the radio will then come up with a bad checksum error. I know I can fix that by reading and writing the codeplug.

The immediate problem is that I can't read the codeplug the way it's set up right now, and after bit-banging, what if I still can't read it? Will I be stuck with a brick, or will the software read it properly now that it shouldn't be looking for the S9000 control head?

By the way, the radio is a T44 (obviously). I'm trying to turn it into a D44.

Bob M.
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kcbooboo
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Post by kcbooboo »

Bit-banged the control head type and ended up with FL 01/82 as expected. Read/wrote codeplug. Had gibberish on the display, but at least now I could read the codeplug. All the modes had junk for names; I straightened them out, added T/A to most of them, then reassigned the control head button functions (they were all set to BLANK). Much much better now.

Thanks Jaymz.

Bob M.
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Post by Will »

Good information, Bob. Thanks.

I found much the same thing with a few real problem radios.
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