Weird Spectra wiring

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fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
What radios do you own?: Desktrac, XTL/XTS's & XPR's

Weird Spectra wiring

Post by fchrist16 »

Alright guys...

Who's come across this before on a command board? The wires are coming off the resistors are yellow/orange at the top, blue/green in the middle and the one lone red wire on the left. No RX audio off the radio and the TX audio is a quick scratchy sound and then drops. All the caps are brand new, as evidenced on the command board...

Image

Ideas?

Regards,

-Frank C.
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Bill_G
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Re: Weird Spectra wiring

Post by Bill_G »

eew. ouch.
fchrist16
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Re: Weird Spectra wiring

Post by fchrist16 »

Care to elaborate. Obviously it must not be good...

Regards,

-Frank C.
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Bill_G
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Re: Weird Spectra wiring

Post by Bill_G »

It may be recoverable, but I suspect some custom mods have been attempted. Got another cmd brd? Or a way to rework this one?
fchrist16
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Re: Weird Spectra wiring

Post by fchrist16 »

Negative on the command board and I'm not sure how exactly I would rework it...

Regards,

-Frank C.
Tim
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Joined: Wed Mar 20, 2002 4:00 pm

Re: Weird Spectra wiring

Post by Tim »

The connections are right around U400 - the Audio Filter IC. Also
looks like some of the components have been removed in the area
of the wiring. Could definitely make a difference in the audio operation!

I have the layout/schematic for a HLN6074A, which appears to be
slightly different than the board you have, but it oughta be pretty
close.

If you can take a better pix (straight down), it might help see what
parts aren't there.

Unsolder the wires carefully & check around for shorts & cuts on the PCB.
He may have cut some traces.

Keep us posted!

Tim
fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
What radios do you own?: Desktrac, XTL/XTS's & XPR's

Re: Weird Spectra wiring

Post by fchrist16 »

Here is another image of it.
Image


If I could get that schematic to figure out what might be wrong that would be great. Meanwhile I'll try and get the wires off carefully...

Regards,

-Frank C.
GlennD
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Re: Weird Spectra wiring

Post by GlennD »

If you have access to spectra lab, I will send you a command board for $10 shipping and handling.
THAT IS REALLY UGLY. IF I DID THAT I WOULD HAVE TO RESIGN AS A TECH!
fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
What radios do you own?: Desktrac, XTL/XTS's & XPR's

Re: Weird Spectra wiring

Post by fchrist16 »

Glenn,

Thanks for the offer but as I'm strapped on cash I can't get a new command board yet so I was hoping to easily fix this. I was able to take off the wires with minimal effort...Beyond there I'm not sure what to do without a schematic or other instructions...


Regards,

-Frank C.
Tim
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Re: Weird Spectra wiring

Post by Tim »

Hi Frank,

Looking from left to right, the most left capacitor is a tantalum.
Then next one right (missing) should be a 0.01uF (C419) . It is in the RX
in line - no audio without it.

The other part that is missing is C409 - 0.0039uF. This is in the
mic audio in line - probably doesn't talk either.

Drop me a note at tahrens at swtexas dot com, and I'll send you
a copy of the schematic that I have. It is a HLN 6094, although I also
have the schematic for a HLN6074A

Tim
com501
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Re: Weird Spectra wiring

Post by com501 »

Someone installed a TransCrypt rolling code voice inversion scrambler.

Look on their website, they should have the modifcation notes which will allow you to reverse engineer this.

If you call them if it is not on their website they can definitely get you what you need.
Will
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Re: Weird Spectra wiring

Post by Will »

What a BUTCHER JOB......

One of the worst I have seen in 20 years...
fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
What radios do you own?: Desktrac, XTL/XTS's & XPR's

Re: Weird Spectra wiring

Post by fchrist16 »

Will it came to me like this...How are my other radios going??

Regards,

-Frank C.
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jackhackett
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Re: Weird Spectra wiring

Post by jackhackett »

did they leave the leads on the caps long enough?

The encryption board wires actually don't look that bad... from what I can see if you unsolder them carefully the component pads should be okay and you can just solder in new chip caps. I've seen worse, with traces all hacked up and stuff.

Are there any other signs of modification? I'm not familiar with those particular modules, but typically an encryption module would have connections for rx and tx audio (the yel/org & blu/grn wires), power (the red.. should also be a ground somewhere) and some method of switching on and off, which could be a toggle switch added somewhere (is there a hole in the radio?), or some way of controlling it with one of the radio's buttons, which could mean another circuit mod somewhere such as the control head. They may have even connected an external switch through the accessory plug somehow, or... if you're lucky, they just ran encrypted full time so no switch was needed.
fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
What radios do you own?: Desktrac, XTL/XTS's & XPR's

Re: Weird Spectra wiring

Post by fchrist16 »

There was a toggle switch on the control head. I didn't think of using that head with this radio as I had re-programmed it for another head. I don't easily see any other mods to this radio besides those wires, which I have taken off and replaced with the help of the local electronics store and their soldering iron/magnifying glasses.

EDIT: Now it's worse than before. I went and put the right control head on and now I'm stuck in the "self check" boot...
REEDIT: Forgot the MLM Board. Now the "self check" boot is gone but the audio issues remain...

Regards,

-Frank C.
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jackhackett
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Re: Weird Spectra wiring

Post by jackhackett »

If it had a toggle I think you should be okay just replacing the two missing caps, basically what they do is insert the encryption circuit into the transmit and receive audio signal paths, and the easiest way to do that is take out some coupling caps... put the caps back in and you should have audio again. I suppose your biggest problem would be finding the caps...
fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
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Re: Weird Spectra wiring

Post by fchrist16 »

Finding the caps and replacing them wasn't that hard...The only issue is the caps are half soldered down and half superglued down...The audio remains the same as before so something else must be going on??

Regards,

-Frank C.
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jackhackett
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Re: Weird Spectra wiring

Post by jackhackett »

Superglue? oh..... not a good idea... that stuff gives off some really nasty fumes if you get it too hot.. I've gotten the smoke from it in my eye a couple of times.. feels like having a hot needle stuck in your eye.

That aside, if the solder joints on the caps are good, there must be something else going on, not sure what it could be.

For soldering in chip components you can put a small amount of solder on one pad, then put the component on and use something like a toothpick to hold it still while you reflow that side, that will hold it so you can solder the other side, finally go back and flow a little fresh solder on the first side to make sure it's got a good joint.
fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
What radios do you own?: Desktrac, XTL/XTS's & XPR's

Re: Weird Spectra wiring

Post by fchrist16 »

Oh I did the superglue after the soldering of the other side! All solder points are good. The radio boots up and checks out fine otherwise it seems. Just this one little issue.

Anyone else have any ideas or do I mark this one up to a "bad buy" and move on? I really don't want to have to do that either...

Regards,

-Frank C.
n4bfd
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Re: Weird Spectra wiring

Post by n4bfd »

I have the exact same problem with a Spectra I just started up today for the first time, and it's my first Moto.
I have very low receive audio, I have to put it all the way up to hear anything, but the "beeps" from the key on the head will blast you out at that level. No TX.
Control head has a toggle switch. Initally when I saw that I thought it may have been a on off since the control head was mounted flush in a console, as it came with the console plate still on it.
I got this from a guy who is selling them on 2 ham boards and on ebay. I've not contacted him yet, as I just found this in the last hour and wanted to see what you guys think.

In the third photo there seems to be a bundle of wires that are in a hole in the middle of the pic, that are cut flush with the board, is this normal?

Image
Image
Image
fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
What radios do you own?: Desktrac, XTL/XTS's & XPR's

Re: Weird Spectra wiring

Post by fchrist16 »

Alright so I was thinking and reading and didn't think "Oh wait my 45w VHF Spectras have the same Command Boards". Well I went pulling and found a good one and now my radio works as needed. So now I have to figure out what else was wrong with that command board.

Thanks again for everyone's help here! Batlabs is the place to be!

Regards,

-Frank C.
fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
What radios do you own?: Desktrac, XTL/XTS's & XPR's

Re: Weird Spectra wiring

Post by fchrist16 »

n4bfd wrote:I have the exact same problem with a Spectra I just started up today for the first time, and it's my first Moto.
I have very low receive audio, I have to put it all the way up to hear anything, but the "beeps" from the key on the head will blast you out at that level. No TX.

n4bfd,

That was exactly like mine...May I ask without upsetting the batlab gods, where did yours come from? There maybe a pattern.

If you want you can PM me with the reply.

Regards,

-Frank C.
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Bill_G
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Re: Weird Spectra wiring

Post by Bill_G »

I would say that confirms an agency was using Transcrypt (or similar) boards, took them out of service, sold them by the lot, and you guys are the lucky recipients of the single sales. Caveat emptor. At least it looks reversible.
fchrist16
Posts: 347
Joined: Sun May 24, 2009 12:23 am
What radios do you own?: Desktrac, XTL/XTS's & XPR's

Re: Weird Spectra wiring

Post by fchrist16 »

Bill_G wrote:I would say that confirms an agency was using Transcrypt (or similar) boards, took them out of service, sold them by the lot, and you guys are the lucky recipients of the single sales. Caveat emptor. At least it looks reversible.
Agreed. I think later today I'm going to take my head apart and examine it...

Regards,

-Frank C.
n4bfd
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Re: Weird Spectra wiring

Post by n4bfd »

I'll PM you where I got it from. To the sellers credit, I fired off a email about it last night, and he responded very quickly, and is sending me another that he has tested. The seller has been selling them for awhile on couple of boards and ebay, so I think if they were all like this something would have come out about it now.
fchrist16 wrote: n4bfd,

That was exactly like mine...May I ask without upsetting the batlab gods, where did yours come from? There maybe a pattern.

If you want you can PM me with the reply.

Regards,

-Frank C.
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