Spectra part number ID

[kf4sqb]

I just purchased a couple of Spectras from a fellow Batlabber, and have a few part number questions about them. These are 800 MHz, remote mount units, with some mods. I purchased them for parts only, now have a question about whether or not the needed parts are compatible. The main parts I need are the front plastic/interconnect board, to change another Spectra from a single DB25 front to a dual DB25 front. This part in these radios has a part number of HLN6161CSP02. Does anyone know specifically what the SP02 means on this board? I know it means that is was a special factory mod of some sort, and need to know if it will render it useless for my application or not. Thanks!


As a side note, these radios are part of what the City of Long Beach, CA recently disposed of, if that helps.

[Jim202]

Good luck trying to find any info on an SPxx for any radio. Like you said this means that some special mod was
done for some special application. In most cases, it's an I don't care, as the radio will function normally.

This could have been something as simple as an extra indicator LED used on the control head. Maybe they
had an external box for tone encode or a data box hung externally.

Hard to tell just what the mod was unless you compare a normal part with the part you have. Bet you will
find that there is an added jumper, a resistor or a cap added.

Jim

I just purchased a couple of Spectras from a fellow Batlabber, and have a few part number questions about them. These are 800 MHz, remote mount units, with some mods. I purchased them for parts only, now have a question about whether or not the needed parts are compatible. The main parts I need are the front plastic/interconnect board, to change another Spectra from a single DB25 front to a dual DB25 front. This part in these radios has a part number of HLN6161CSP02. Does anyone know specifically what the SP02 means on this board? I know it means that is was a special factory mod of some sort, and need to know if it will render it useless for my application or not. Thanks!


As a side note, these radios are part of what the City of Long Beach, CA recently disposed of, if that helps.

[kf4sqb]

Good luck trying to find any info on an SPxx for any radio.

Yeah, that's kinda what I figured, but there's always that chance (you know, like the chance a snowball has in Hades) that someone has run across it before and knows something about it.

Hard to tell just what the mod was unless you compare a normal part with the part you have.

Those plans were already in place, but I figured, what the heck, the worse I can get for asking are good luck wishes.

[akardam]

HLN6161CSP02 comes up as REM MT RSSI DATA BD. Perhaps for sending RSSI data to another device or computer?

In any event, you could examine the command board and see if it has a SP part number. If not, and you can't see any visible mods to a stock board (wire jumpers, etc), then you'd probably be OK to put a stock remote board on the radio and call it good.

[kf4sqb]

akardam, the command board shows a part number of HLN6394ASP02. As for putting stock interface board on this radio, I need to go the other way. I want to put the interface off of this one on a stock radio.

[GlennD]

We did not use the front connections at all. The VRM500 connected to the rear DB15 and we have no documention on the front interface.

[kf4sqb]

Ah, the one person I was hoping might know something about this. And you don't. Just my luck here lately. Oh, well, I'll go with the "put them side-by-side and compare" method. Thanks to everyone who replied, and I'll certainly post any differences I happen to find, for the use of future generations .

[Mike B]

I found the schematic for the HLN6161C in the Spectra A4 Control Head manual (6881109C34-O). The HLN6161B schematic is in the A5 and A7 Control Heads manual (6881109C33-O), Detailed Service manual (6880102W61 section PW-7528-O), Spectra UHF Service Manual (6881071C05-A), Spectra 800 MHz Service Manual (6881074C45-O) and Spectra 900 MHz Service Manual (6881074C40-O).

It appears to be a fairly common schematic, so look through any Spectra manuals you can get your hands on. At least it will show the optional configurations for the normally un-installed components and give you a guide to all the jumper locations (these are the most likely candidates for a SP version difference, but not the only candidates).

Unfortunately the schematic is on a 3 page fold out. If you can't find the schematic send me a PM.

[kf4sqb]

After getting a copy of the schematic of the board in question (thanks, Mike!), I have sat down and done a little comparison. So far, this is one strange puppy. It has U600 (an OPamp, labeled as an "audio mixer"), which the schematic says is normally not installed, installed and connected to what should be the RSSI circuit and what should be the spare-2 circuit, instead of the filtered audio circuit, like it normally would be. That's as far as I've gotten so far, and it'll probably take me a while to finish this up. After I finish tracing all the circuits, I'll try to alter the schematic to reflect the differences, and make it available to anyone who needs it, as well as documenting what changes I make to make it compatible with a standard HLN6161C. That's going to take a little hacking on the board's traces, as the board layout is different enough to require it in a few places. This is, unfortunately, not one of those "a few jumpers different" kind of SP's. There are a few places that traces and solder pads are in different places or non-existent, as well as a few places that solder pads that aren't normally there, are there. Its a good thing I love a good challenge...

[motorola_otaku]

I have one of those too. As Glenn indicated, they were used on radios that were used with VRM500 modems in mobile data applications. The one I got was used without any control head attached.

I couldn't tell you whether it would work on another radio, but I can tell you that you can plug an old-style A5/7 remote control head into the left DB25 port and get full normal functionality out of the radio it was originally used on. As for the RSSI part, I seem to recall reading something in the VRM500 documentation about it looking for RSSI indication from the radio, so the sum total of all of these SP mods is probably to supply it on one of the DB15 lines.

I can also provide hi-res pictures if needed.

[kf4sqb]

Motorola_otaku, you're braver than I am! I wouldn't even think of hooking up an SP anything without verifying exactly what the SP consists of. You do, however, appear to be correct in that most of the changes so far seem to be related to the RSSI circuit, with a few changes to the filtered audio circuit as well. I've traced almost all of the circuits in the SP board out against a schematic of a "normal" HLN6161C board, and almost everything else is the same. One thing I would like to know, is what purpose does the MOSfet Q600, located between the pin-header that plugs into the radio and the left-hand DB25, serve, and is it normally present? It is absent on this board, as well as having a few changes made to the circuit it is connected to.

As stated earlier, I will post a full "review" of what I find out, as well as a step-by-step of what I did to change this board to a "normal" board, after I get finished with the project. Thanks to all who have helped and given input so far!