Service Manual for Motorola Spectra ...

[Alex T.]

Hi,

I have an old Motorola Spectra and need a Service Manual to find out
where to search for a 1kHz tone which can be heard i the speaker when
listening to a transmission, while the display light is set to High,
Medium or Low,

There is nothing to hear when the display is switched off.

Have any of you had the same problem with this radio, and maybe know
hof to fix it?

The Spectra Model Number is: DA7KX+067W (VHF)

[Dr. Anton T. Squeegee]

Post by Alex T.
Hi,
I have an old Motorola Spectra and need a Service Manual to find out
where to search for a 1kHz tone which can be heard i the speaker when
listening to a transmission, while the display light is set to High,
Medium or Low,
There is nothing to hear when the display is switched off.
Have any of you had the same problem with this radio, and maybe know
hof to fix it?

This is often caused by leaky or dried-out electrolytic surface-
mount capacitors on the display PC board. Repairing it requires two
10uF/16V surface-mount caps, the proper desolder/resolder equipment, and
the skill to use it.

The detailed service manual, covering all Spectra models, is
Motorola part number 68-80102W61, current list price of $40.45.
Considering that the thing comes in a two-inch thick binder, and is
nearly the size of a small phone book, that strikes me as a pretty
decent deal.

I would also strongly recommend that you get the basic VHF service
manual as well: 68-81070C95, current list price of $24.75. It contains
interconnection and accessory information not found in the detail book.

Both manuals can be readily ordered from Motorola at 1-800-422-
4210.

Post by Alex T.
The Spectra Model Number is: DA7KX+067W (VHF)

FYI: That's not a valid Motorola model number. That is, in fact,
the FCC ID of your radio. Motorola had a problem with their model/serial
labels during the time the Spectras were still in production, in which
the radio's actual model number and the FCC ID were transposed.

The actual model number will likely look something like this:
D43FWA7JA7AK, or some similar appearing string.

If you decide that you do not want to do the repair yourself, or
if you lack the equipment to do so, I can do it at rates considerably
lower than most commercial shops. Visit my web site for details:

http://www.bluefeathertech.com/rf.html

I hope that helps.

[Alex T.]

Hi Anton,

Thanks for replying. :-)

On Thu, 17 Feb 2005 19:02:06 -0800, Dr. Anton T. Squeegee

Post by Dr. Anton T. Squeegee
This is often caused by leaky or dried-out electrolytic surface-
mount capacitors on the display PC board. Repairing it requires two
10uF/16V surface-mount caps, the proper desolder/resolder equipment, and
the skill to use it.

Thanks for the info, i was wondering weather or not it could be those
caps. :-)

Loading Image...

I assume you mean the two caps to the right of the IC 9315XB ... ?

Thanks for the info about the Service Manuals, i might consider it, if
i can't figure out the problem. :-)

Post by Dr. Anton T. Squeegee
D43FWA7JA7AK, or some similar appearing string.

Ok, I didn't know that.

I can see that D43KXA7JA7BK is printed on the label at the back of the
radio, as the ID No.

Post by Dr. Anton T. Squeegee
I hope that helps.

Me too. :-)

[Dr. Anton T. Squeegee]

In article <***@4ax.com>,
***@qth.dk says...

<snippety>

Post by Alex T.
I assume you mean the two caps to the right of the IC 9315XB ... ?

That would be them, yes. Those are the two key suspects for an
awful lot of problems, including the tone you describe and dim or no
display.

Post by Alex T.
I can see that D43KXA7JA7BK is printed on the label at the back of the
radio, as the ID No.

That's more like it. What you have there is a 35-40 watt output
unit, dash-mount, secure-capable (with the appropriate daughterboard,
encryption hybrid, key variable loader, and cable), 128-mode (channel)
capable. The 'A7' towards the end indicates the control head type, in
this case a full-keypad unit.

Such radios rarely have trouble covering the amateur 2m band in
its entirety, no matter if they're Range 1 or Range 2 units.

Happy fixing.

[Alex T.]

Hi Dave and Anton,

Thanks for info. :-)

I've changed the two SMD caps with some non SMD caps, but it didn't
solve the problem.

I've tried to disconnect the inputs on TDA7256 LF amplifier just to
check weather or not the tone is before or after the LF amp.

Since there is no tone to hear in the speaker when the inputs on the
LF amp. are disconnected, the problem must be before the LF amp.

Just to be sure, that the caps next to the LF amp. are ok, i changed
them too, also to non SMD caps.

There's plenty of space for non SMD caps. :-)
(And I didn't have any SMD caps. :-)

Do you have any other ideas to what the problem could be?

[Pun Krocker]

Post by Alex T.
Hi,
I have an old Motorola Spectra and need a Service Manual to find out
where to search for a 1kHz tone which can be heard i the speaker when
listening to a transmission, while the display light is set to High,
Medium or Low,
There is nothing to hear when the display is switched off.
Have any of you had the same problem with this radio, and maybe know
hof to fix it?
The Spectra Model Number is: DA7KX+067W (VHF)

http://www.eserviceinfo.com/