Astro Spectra accessory connector

jackhackett · Post by **jackhackett** » Tue Apr 26, 2005 12:45 pm

Have any of you converted an Astro Spectra dash mount to enable PTT and MIC HI to hook a mic or remote to the rear accessory connector?
Before I rip the thing apart and start changing jumpers I figured I'd check to see if one of you might have specific instructions on how to do it.

Alan · Post by **Alan** » Tue Apr 26, 2005 10:01 pm

Yes, we have done many.
Thee are 2 jumpers. I would have to look at work to confirm which ones. One is for PTT and the other is for mic Hi.
It can also be ordered from factory jumpered that way.

Post by **wavetar** » Wed Apr 27, 2005 5:27 am

Yes, Al is correct. The jumpers which need to be moved are:

Remove JU518, place it in JU500 (PTT)

Remove JU521, place it in JU513 (Mic Hi)

I have pictures of where the jumpers are located on the command board, if you need them emailed to you. Be aware, the locations can vary slightly for different board revisions.

Todd

BDB · Post by **BDB** » Sun Sep 11, 2005 11:09 am

I would interested in the locations myself. I recently interfaced a Firecom intercom system to an A4 Astro Spectra and had no luck getting PTT from the rear accessory connector. I ended up going into the mic jack to get the desired functionality. My original intention was to use the rear connector and have the hand microphone attached for secondary use. I would still like to be able to set this radio up in that fashion.
Thanks !

Post by **xmo** » Sun Sep 11, 2005 1:38 pm

The aforementioned "jumpers" are actually zero ohm surface mount resistors. They are physically located on the underneath side of the command board. Changing them requires virtually complete disassembly of the radio - remove the control head [or remote mount front], the top cover, the PA, the vocon, and finally the command board.

You should have surface mount rework equipment and a static safe work environment available.

You will need the basic and detailed service manuals - 68P81076C20 and 68P81076C25 respectively.

The basic manual shows the recommended disassembly and reassembly procedures. The detailed manual has the schematics and board layouts.

Also, Motorola recommends replacing the screws that hold the VOCON board in place since they are self tapping and their threads become plugged with metal shavings from the initial factory installation.

In addition, there are specific torque specifications for all the fasteners in this product.

BDB · Post by **BDB** » Sun Sep 11, 2005 2:01 pm

Well isn't that a kick in the butt. I was hoping the fix wouldn't be invasive. Live and learn

Thanks for the info

Post by **wavetar** » Sun Sep 11, 2005 2:48 pm

If you still want to do it, I can email you pictures of the component locations. As XMO pointed out, there is a fair amount of disassembly involved...although I've learned to do it without having to remove the PA module, which saves a ton of time. I wouldn't worry about the recommendation to replace the VOCON screws...I've never had a problem with re-using them. As far as needing surface mount rework equipment...it's moving two surface mount chip resistors...if you've done it before with a regular soldering iron (which isn't a big deal), then you can certainly do it here. Let me know,

Todd

BDB · Post by **BDB** » Sun Sep 11, 2005 2:52 pm

Todd,
I'd like the photos of the component locations. I have the service manuals but the photos are a big help. Please email them to me. My email address is in my profile.

Thanks !