Batboard

Greetings Earthlings....

I just aquired a Motorola s1057B Portable Test Set which I wish to use with Mitrek radios for tuning, maintenance etc.

I know that this test set will work fine with these radios, but mine didn't come with any cable sets or anything.

Is it worth trying to find or make a cable for it for Mitreks? Also, what exactly does a Peaking Generator do? It has that option installed.

I'm thinking that if I can find stuff for it such as a deviation meter option and the cables I need, it probably will do everything I need for routine maintenance and tuning.

Any information is appreciated......

My two bits worth:
Keep in mind that the Mitrek was the last radio that was intended to be serviced with this test set.
Being an antique it has some features not found on "modern" test sets.

There were many optional modules for the test set.
These were often used on only one system, such a police, fire or taxi.
The "peaking generator" requires a crystal on your particular frequency.
It generates an un calibrated signal for adjusting the RF stages of a receiver.

There is also an IF generator. 455kc is standard, optional crystals for your particular IF.

There is a 1KC tone generator for setting TX deviation.

Modulation meter module.
I have seen these, but never used one.

Field strength meter, used for tuning low band portable antennas, etc.

The Mitrek cable is the same as the Motrac, Mocom series.
I probably have a cable., and manuals.

The original cable had a 11pin tube base, an adaptor cable was used for
the "relay socket" used on Motrac and Mocom.

There are several other cabels as well.
Under NO cirucmstances remove the screws from the test set end plug.
It will fall apart into many little peices.

Ok Bernie thanks. I thought you might know about these. It should work great for me because I'm only going to use it with the Mitreks which are in my ham repeater/remote base system....

The test set works great, i have a S1057A and a S1059A, both in near mint condition that work flawlessly. I was lucky to snag them when a local shop closed down a few years back and sold all their old test gear.

First thing you want to do is remove the back inside cover and check the condition of the internal battery, its a small battery that supplies power for zero centering of the meter. On most test sets i have come across that battery was starting to leak, and it will start eating away the traces.

It's a 1.5v N size cell. They are still easy to find, just look through the batteries at any radio shack or local super store, usually you will find them with all the camera batteries.

After you replace it adjust the zero center adjustment, the control is located on the left side through a hole in the back shield. It's easier to just do this after replacing the battery and before replacing the back shield. The back shield is easy enoug to remove though. Just a couple nuts and small screws around it and then the entire piece comes off. Its a good time to spray down the switches lightly with some contact cleaner and work them around a few times, clean it out, you wouldn't believe what you find in some of them, and replace that internal battery and adjust the zero center.

If you need a manual i can send you a .pdf file if your inbox will take a file that is just over 7mb in size. Its for a A model, but there really isn't much difference between them. They made a few small revisions, but otherwise electrically the same.

The Mitrek cable is easy enough to make if you can scrounge up the parts. The micor cable is more difficult because its hard to find a suitable replacement for the square pin plugs. If you need a picture to show what the cables should look like i can get one taken of my cables. The main thing though, is having the cable that plugs into the test set, those are hard to find and duplicate!

Coolness, thanks for the info. I'll look at that battery. The unit I've got looks like railroad surplus and is kinda beat up but nothing's broken. I'll take you up on that manual since I don't have any documents at all on it. Send it to [email protected], and thank you. I might know a guy locally who may have cables too ....

I'll fire over a copy of the manual!

Just curious what a reasonable base price range would be for 1056B set? I have had one offered to me.. need to see it in person to check cables, condition, etc. Just need a starting point for negoiations..

maxjam, where in southern MN are you? I'm down in the same neck of the woods, well actualy SW MN.

I paid $30 for the last one i bought, came with all the cables and a bunch of Moto adjustment tools, manual, etc. The only thing i didn't get was the peaking generator, and deviation meter panel, it just has blank panels instead of the options.

I have both the TU546 and the 1059B. Neither seem to work. Thanks for the info on the internal battery. Didn't know it existed. Thanks
Craig

The peaking generator is really useful if you work on a lot of older stuff (of any type) and want to test crystals, as you get a relative output indication on the meter. As a signal generator, it seems pretty useless to me, since most of us have a service monitor or a regulator signal generator.

In the original TU546 test sets, you had to change the meter when you installed the deviation measuring panel. I don't know why, since the original meters had the deviation scale printed on them already and the meter which was supplied with the deviation measurement panel looked identical.

As long as we are talking about the test sets, for those who didn't know, there is a cable storage box inside the chassis of the test set, I have seen literally dozens of these for sale, where the seller didn't know the cables were inside. And I agree that 20 to 40 bucks is normal.
Something else that no one mentioned is that you must make sure the test set you have is modified.
The modification started with the Micor, but my memory tells me it is needed for nearly all radios after the Micor also. Bernie, do you remember any more about that?
The purpose of the mod is to keep from frying the audio stages as I recall.
The difference being audio referenced to ground versus Spk HI & Spk Lo differential like most new radios.
I haven't seen too many that weren't modified.
The Motorola service bulletin was 68P84307A01 on the mods.
It also states that test sets and cables with a manufacturing date of January 1, 1970 don't need modification.
So a S-1056A will need it (but probably aready done) and S-1056B WON'T need it.
So the suffix B models were factory done, and the test set cable SLN6056A-4 or higher was done.

My two bits worth:
I remember the mods but that was over 30 years ago, and another tech did the work.
I do not think that I have any information on the modification.
It probably had somthing to do with final PA metering.

I'm still trying to tune a mitrek with my 1056b, I don't get readings on meter positions 2 or 6 receive. I can, however, get the proper readings with a digital vom. Was there any cable mods that needed to be done. I've noticed that the speaker works in my old TU-546 but not in the 1056b. I'm using the 20 pin to 11 pin cable that came with the TU-546 and the matching adapter to the mitrek. I need to finish tuning and it is much easier with the test set. (my TU-546 seems to be dead as a doorknob, new batteries no readings for zero etc.). Is there anything I should check on the test set? Does the cable need some mod I don't know about. Sure could use some help. Thanks
Craig

My two bits worth:
If the meter reads at all, if you can get meter 4 to center the meter is likely ok.

If the only problem is with meter 2, or 6 perhaps the contacts on the meter switch are tarnished.
Just run the knob around a few dozen times.

The metering cables for MOTRAC, MOCOM 30, 35, 70 are all the same.

Don't expect to use meter 4 on the receiver. Instead set your frequency meter for the injection frequency. (10.7MHZ below carrier)

I can get the meter to zero on position 4 no problem. But it reads nothing from the radio on any position other than audio position (meter reading but no sound). Anything else to try. Need to hey yhis repeater working. The mitrek can hear a radio, but if you get more than 100ft (estimate) from the repeater it will kerchunk but will not pass audio. If you are close it works great. Suggestions? thanks for all the replies.
Craig

PETNRDX do you have a copy of that test set mod service bulletin? Can I get a copy? Thanks
Craig