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High Power Astro Spectra Cable - W3 head

Posted: Tue Feb 27, 2018 8:54 am
by RFrat
Hi everyone,

New here, please excuse the question if it's already been answered.
I have a VHF high power astro spectra, model T04KLH9PW3AN designed for the W3 head. I'm attempting to make my own cable, since the "Y" cable seems to be unobtanium, either from cost or availability. I wired a male DB25 to bring out ignition sense (pin 3) and speaker audio (24/25). The rest of the pin go straight through to the female end, pin-for-pin as they are on the W3. The W3 does not have many pins, so I only connected the ones that are required. ie, pins 24 and 25 exist on the head, but I didn't connect them to the deck since I figured they are only needed for the speaker.

The problem is, I get the fail code, "FAIL 01/90"; general hardware failure. A few idiot checks:
- I've cycled the power. No change.
- The RIB is not plugged in when I power it up.
- Using the leftmost DB25 (near power connector)
- DC input is 12V
- ignition sense seems to be correct; radio powers off when I disconnect the pin.
- I have not attempted to read/write from the radio. Internet auction claimed it was functional, and a friend who purchased the same model from that auction has successfully read/written to their radios.

Thoughts? I either have the wrong pinout, or it's DOA.

Thank you!

Re: High Power Astro Spectra Cable - W3 head

Posted: Mon Mar 05, 2018 10:33 am
by RFrat

So, we checked my radio on a friend's setup in his car. The radio booted fine, so I thought I must have had the pinout wrong. I started over, followed the diagram exactly, and it didn't work (same error). This was a 6" piece of Cat5, mind you. I then made a loop in the wire, tried it again (for some reason), and it worked. Completely puzzled, but I was able to tape wires in place to get the thing programmed, so I must have done something right.

I did use solid-core Cat5, so maybe a broken connection? DIYers beware if you attempt to make a cable.

Re: High Power Astro Spectra Cable - W3 head

Posted: Mon Apr 09, 2018 4:53 am
by flyinace09
I've seen some weird things come out of Motorola products specifically when dealing with the SB9600 bus. It seems to REALLY be sensitive to shielding and interference. If you look at the factory cable, it has the RS-232 and SB9600 in their own twisted and shielded bundles with their own drain wire. The rest of the wires go straight-through for ignition sense and speaker audio.

I have been looking at making a second cable (I was lucky enough to find a cable with the radio-end DB25 cut off that I just needed to re-pin and put in a new backshell...) and my method was going to be to use multiple runs of Belden 8723 (4 wire shielded) together to get what I needed and retain proper shielding of what is needed to be protected. There probably is a better suitable cable out there... just one I haven't found easily on sale yet.