Batboard

Hey guys, I have two Spectras (both Type II 800MHz) ... with a A5 (remote mount) and A7 (HLN6075 dash mount) heads respectively. On both of them, a few digits on the display are beginning to fail. They're very dim. I figure I can just swap out the control heads since they're socketed?

Forgive me if I'm a little dense, but I'm a confused as what they're saying on this site:
http://www.open.org/~blenderm/spectra

Are they saying I CAN swap the control heads out with any other A-series control head, but if I put an A7 on a radio originally fitted with an A5 head, the extra features on the A7 head will not function on it, it will act as an A5-head.

If so, anyone have two dead Spectras they wanna get rid of?

You can swap those heads w/o any problems. Then just read it and change the head to enhanced in radio-wide settings.

videonerd wrote:Hey guys, I have two Spectras (both Type II 800MHz) ... with a A5 (remote mount) and A7 (HLN6075 dash mount) heads respectively. On both of them, a few digits on the display are beginning to fail. They're very dim. I figure I can just swap out the control heads since they're socketed?

<snippety>

You should also give consideration to repairing the flaky heads by replacing the display. It's still available from Motorola, though replacing it does require desoldering equipment.

One thing you should check for as well: There are two electrolytic suface-mount caps on the back of those boards which tend to dry out and leak. They should be replaced on general principles, especially if the radios were made before 1992.

Happy tweaking.

questron: how difficult is it to swap from a dash-mount head to a systems 9000 head? or remote mount head?

Sys9000 head takes a little programming work, but a remote head is as simple as getting the right parts(3 total). This breaks it down quite nicely: http://www.open.org/~blenderm/spectra/#combo

i guess i should have read here first


[/quote]questron: how difficult is it to swap from a dash-mount head to a systems 9000 head? or remote mount head?[/quote]

Be sure to replace those two 10uF 50v caps but also consider replacing the VFD driver ic (SN65518FN) with a new one. I've replaced two in the past and both helped the displays come back to life. If you study the service manual a bit you'll figure out that the voltages and waveforms applied outside of those two 50v caps are like a war zone. I'm guessing what happens is that the caps fail allowing the voltage spikes through to the chip and effectively putting it into slow bake. The part from Motorola is somewhere around $11 as I recall. An alternative part number is UCQ5818EPF. I beleive both chips are discontinued though.

where would be lucky enough to get a service manual? I have MOS access can i get it thru there?

I have a businessonline account with Motorola. If you are a business and fax them a vendors license then you will get dealer pricing on stuff you buy through their online store. Otherwise you'll get list price which can be quite a bit higher in some cases. In my case I became a sole proprietor and secured a vendors license for another purpose that never panned out but it did in this case.

If you already have an account with them then all the better. The service manual is $29.25 as of last night. Also, I did some digging into the SN65518FN chip and found that the replacement has been replaced. The latest and greatest chip number is A6818 manufactured by Allegro Micro. It seems that in onesy-twosy quantities it costs somewhere around $5.50 or so plus shipping and handling.

If you swap from an A5 head to an A7 head, does changing the control head setting from standard to advanced enable the extra buttons? If not, what is required to do that? What if you were changing an already remote-mount A5 head to an A9 sys9k head? Is it bit-banging or forcing a different codeplug in with Lab to make these changes? What if your MLM is too new for Lab, then what?

Bit-banging or forcing a codeplug will accomplish the task. I find it easier to find a codeplug with the head, band, and majority of the feature set I want in it and then load it. After loading the codeplug into the radio I then use the bitbanging tool to go through and find the feature string which I then copy to the command board. Get Fail 01/82. Read codeplug. Write codeplug. Radio works normally.

Or you could try to hunt around in the codeplug to bitbang the band, head, etc. I've had limited success with that but it could be a problem on my end (namely me).

What if your MLM is too new for Lab, then what?

Still wondering how to get around this part...

I went into lab software with a hex editor and changed all occurances of the release number to the newest release of non lab software that I have. For instance, my lab version is really version 4 but it says it is 06.05.00 or whatever the newest release is. This gets around the the MLM too new for lab problem. It works just fine even reading and writing the codeplug from lab. I have noticed no problems at all.

One advantage I find in lab that I don't find in the newer releases of non lab software is the ability to specify a particular trunked system to be receive only. This is useful for a radio that is used for ham conventional but also might have a trunked public safety system or two in the codeplug. This prevents accidental transmits of your callsign onto a public safety system that is most likely being recorded. My radios are all programmed this way because I like to listen to trunked systems but I'm not interested in interfering in any way with any trunked system, public safety or not. Of course, all the auto affiliation stuff is turned off too.

Just be sure to not distribute the modified lab software without stating such otherwise a whole bunch of people will get a big woody over a new lab release just to find out that it's not really new at all.