MAXAR 80: Help! Frequency Question

[TrishMvhl]

Hi Everyone-

Help! I have five MAXAR 80 units, a base station, about 8-10 various antennas. I put them for sale on the local Craigslist, and someone asked me what frequency they were. I have no clue.

These items have been in storage and belonged to my Dad, who I cannot ask because he passed away last year. Is there an easy way for a layman like me to find out what frequency they are? I've been Googling and trying to educate myself about them but I think you guys are my best hope for a clear answer!

 

[mmckenna]

There should be a model number somewhere on the chassis that would be good to share with us. That would at least tell us the band.

The Maxar 80 is crystal controlled, so you'd have to look at the crystals in the radio to get an idea what frequency it was on. Likely the crystals won't have the actual transmit or receive frequencies. Some simple math would convert that into a TX/RX frequency.

 

[TrishMvhl]

mckenna-
Thank you for responding. The model number is D51TSA8000AK

I don't know what the crystal looks like or where to find it. I took off the back and snapped a picture. Would it be in this area or deeper in the guts of the unit?

thanks,

Trish M.

 

[ElroyJetson]

The crystals will be in the main section. You're showing the power amplifier.

As they're not narrowband and they're rockbound, they're both all but totally useless and actually not legal to transmit with outside of the amateur bands, IF, that is, you're licensed for that.

If anybody offers you ANYTHING for them, take it.

 

[KevinC]

Your antennas appear to be a mix of CB and possibly VHF...

https://newyork.craigslist.org/wch/ele/d/5-motorola-maxar-80-2-way/6627629218.html

 

[TrishMvhl]

Kevin-

Yep, that's my Craigslist ad. I'm just offering everything together as a jumbled package deal, haha. We used a CB radio in Bronx when I was a kid. But I don't recall seeing these MAXARs except in storage. Don't know if Dad actually used them or if someone passed them along to him.

 

[KevinC]

Looking at this...

Table of Motorola model number suffixes - a Rosetta Stone article

The radios appear to be "low band", which would explain the CB looking antennas.

Maybe someone else will chime in, but I'm going with low-band...but I could be wrong.

 

[mmckenna]

So the radio will cover the frequencies between 25 megahertz to 54 megahertz. Model number says it's somewhere between 51-75 watts RF output. Single channel. Capable of Digital Private Line.

The two crystals would be buried under the top plate on the radio. The part you are showing is the RF amplifier.

I'd not dig too far into the radio. Anyone who's serious about using it would need to recrystal it anyway. Those are awfully old radios, and with that frequency spread, the only likely user for it would be an amateur radio operator interested in putting it on the 6 meter amateur radio band.
It'd be a good project for someone with time on their hands and the desire to make it all work, but those radios are out of date and the 25-50MHz band isn't often used for commercial radio use anymore.

Might be able to get a few bucks for it all on e-bay, but that's likely about it.
There's a few on there now:
https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=Maxar+80&_sacat=0

 

[TrishMvhl]

The crystals will be in the main section. You're showing the power amplifier.

As they're not narrowband and they're rockbound, they're both all but totally useless and actually not legal to transmit with outside of the amateur bands, IF, that is, you're licensed for that.

If anybody offers you ANYTHING for them, take it.

Any information about them is helpful, thanks. I''d like to be able to tell the interested person something. (Actually here's been two people interested, which is more than I expected!) I of course would prefer they go to someone who might have use for them rather than the e-cycling heap.

 

[TrishMvhl]

So the radio will cover the frequencies between 25 megahertz to 54 megahertz. Model number says it's somewhere between 51-75 watts RF output. Single channel. Capable of Digital Private Line.

The two crystals would be buried under the top plate on the radio. The part you are showing is the RF amplifier.

I'd not dig too far into the radio. Anyone who's serious about using it would need to recrystal it anyway. Those are awfully old radios, and with that frequency spread, the only likely user for it would be an amateur radio operator interested in putting it on the 6 meter amateur radio band.
It'd be a good project for someone with time on their hands and the desire to make it all work, but those radios are out of date and the 25-50MHz band isn't often used for commercial radio use anymore.

Might be able to get a few bucks for it all on e-bay, but that's likely about it.
There's a few on there now:
https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=Maxar+80&_sacat=0

My hero! This is so helpful, thank you mmckenna! I'll pass along this info to the interested party. I didn't want the hassle of Ebay, which would involve packing up heavy equipment, so decided to go the local Craigslist route.

I can take my Mac apart and put it back together. This stuff is a whole different universe though!

Thanks again to everyone!

 

[cmdrwill]

The crystals will be in the main section. You're showing the power amplifier.
As they're not narrowband and they're rockbound, they're both all but totally useless and actually not legal to transmit with outside of the amateur bands, IF, that is, you're licensed for that.

If anybody offers you ANYTHING for them, take it.

Agreed.... but NOT totally useless.

They are Low Band radios which do not have to be narrow band.

They came in three different 'bands':

25 to 30
30 to 36
36 to 42
42 to 50

And to find out for sure you need to look at the transmit crystal.

 

[TrishMvhl]

Thank you, cmdrwill! If there's a buyer I will let them do the surgery needed to find the crystal.

I will edit the Craigslist ad with additional information you guys have provided. It's very much appreciated!

 

[cmdrwill]

FCC Type Acceptance TX Data CC1144

 

[ramal121]

Getting individual replacement crystals for radios is just about impossible these days as many of the companies that did them are out of business.

If you can find a way to fire them up and confirm they talk to one another then you could sell them to someone who's looking for some bootleg hunting radios (which we all know is illegal without a license).

 

[N1GTL]

Table of Motorola model number suffixes - a Rosetta Stone article

 

[RFI-EMI-GUY]

Being low band, it is likely they are simplex radios and with luck they might actually talk to each other.

Having worked on Maxar 80's in the lab in 1980, I have some familiarity with the crystals. If the OP wished to post the frequencies listed on the individual crystals in the radios, I will try to cipher out the operational frequencies. There will be at least two removable crystals (TX and RX) in these single frequency radios with different numbers. Be sure to put them back in the correct holder. They are held in with a wire bale.

Motorola Maxar 80 radios were pretty well made given that they were to compete with Japanese radios of the time.

 

[RFI-EMI-GUY]

(snip)

The two crystals would be buried under the top plate on the radio. The part you are showing is the RF amplifier.

(snip)

To find the crystals:

1) Tighten the PA module back on
2) Remove the volume and squelch knobs by prying them carefully off the shafts. The rubber might be crumbly, so pulling the rubber might be bad.
3) Remove the microphone and any bracket screws on sides.
4) At the bottom rear of the housing are two slots where they snap to the chassis. Use a sturdy flat blade screw driver and with a small amount of prying you can loosen and slide the entire housing off.
5) On the component side of the circuit board, look for two black plastic sockets which will each have one shiny TX or RX crystal plugged in. Take note which side of the socket the crystal is plugged in so you put them back in the right place. There will be a wire bale holding them in. There will be some other shiny IF crystals soldered to the board. Those are the same in every radio and should say 10.7000 on them. If not, take note of what they are marked. The plug in ones are your target.
6) If you can't find the TX and RX crystals, they might be mounted under the speaker and DPL board. You can remove those with a nut driver and move them aside. The DPL board will have a plug in module with a three digital octal number like 023. Write that down as well.
7) Write down the frequencies on those crystals. They will have a mathematical relationship to the actual frequency the radio transmits and receives on. I can "cipher it".
8) now you will know exactly what frequency and radio service it is good for. With a bit of luck, there is a small trucking company out there that can use them.

These being low band tilts the "maybe useful meter" a bit closer to the right.