Realistic Navaho TRC - 57

[Dwitherspoon]

I just picked up a Realistic Navaho TRC - 57 off of Ebay for 85 dollars shipped. It's a 23 channel base station from 1976. Does this have 80 channels SSB or 23 on lower and then 23 on upper? information on this isn't available on the net other than the obvious 23 channel limitation before Jan 1st 1977. I was also under the impression I could alter the radio for all 40 channels, but not crucial. CB radio repair people who could freshen the box and caps are welcome to chime in as well.


Best,
Dustin.

 

[DaveJacobsen]

A 23 channel radio is a 23 channel radio.
You have 3 modes: AM, LSB, USB. They operate on the same frequency (channel), it is the modulation that changes. So you have 23 channels.
I'm not aware of a channel board to expand to 40,but that doesn't mean it doesn't exist.
Yes, I would think you'll want to replace the electrolytic capacitors. Doing so is trivial.

 

[KB4MSZ]

It is a 23 channel CB radio with SSB capability. There is a very common misconception that SSB "adds" channels to the range of usable frequencies on a CB. The fact is that the SSB mode can be used on any of the 23 channels, but this occupies the channel and does not further divide it up for traffic beyond what the channel had to begin with. As to expanding the radio for more frequencies I suppose it could be done but with a rig this old it would be akin to attaching a motor to a butter churn.

 

[Dwitherspoon]

As to expanding the radio for more frequencies I suppose it could be done but with a rig this old it would be akin to attaching a motor to a butter churn.

I don't know, she's a sexy lady. The interesting part is the radio is from canada. They made some minor changes visually. I'm very curious. I would have gone with the TRC-457, but I'm not a millionaire and a 148gtl mobile doesn't look right on a desk. I heard of mike's radio repair based out of the east coast somewhere. He's supposed to be able to work magic.

 

[prcguy]

This radio has a PLL synth and should have some mods available for more channels.

 

[KEWB-N1EXA]

I don't know, she's a sexy lady. The interesting part is the radio is from canada. They made some minor changes visually. I'm very curious. I would have gone with the TRC-457, but I'm not a millionaire and a 148gtl mobile doesn't look right on a desk. I heard of mike's radio repair based out of the east coast somewhere. He's supposed to be able to work magic.

Well ... The 148GTL is a big seller and gets a good price because you can modify it. By adding 3 switches to the Processor and changing the input
coding from the channel selector you can go below or Above 40 channels for Freeband Operation or just to listen.

An Ebay $12 frequency counter can tap off of Test Point 106 using a 180 ohm resistor to get the Receive and Transmit Frequency.

The power really cannot go to much by the variable pots but it can go a watt or so Higher 7 Watts AM and 15Watts SSB and
you can turn it down for driving External Power amps.

The AM and SSB Are processor driven but its very quiet and stable compared to alot of the newer CPU rigs that are hissy in sound.

Looking back at the TRC-57 and 23 channels... Back in the 1976-77 era many of these radios were PLL Crystal controlled. 12 or so Crystals
mixing the frequency's would generate the channel to be on. The TRC 57 is Ok to try the hobby out but The activity is on the upper
channels I leave mine on Ch38 LSB for Propagation Listening or listen to the Locals on Freeband.

Next is what are you doing fr an antenna ? Building or Buying ?

Pete N1EXA

 

[Dwitherspoon]

I have a firestik 7 foot fiber attached to a heavy duty magnetic mount which is attached to a one inch thick, 5 inch in dia a36 steel disc. The magnetic pull was so great that it cut my finger attaching. It was impressive. I have am RM italy kl-203p which should do the trick.

best,
D.

 

[KB4MSZ]

There is only a 5 inch diameter ground plane beneath the antenna? No other surface metal?

 

[Dwitherspoon]

Yes. I would say I’m getting lower than 1.1 SWR. Haha, it slams the needle! I was worried that the size would be a factor as well, but it hasn’t been. Haha, which is good, because I can’t physically separate the steel disc from the mag mount. Tried for 25 minutes, no dice.

Best,
D.

 

[prcguy]

Antenna performance is not all about the match, its how well it radiates. The match might seem ok with virtually no ground plane but the antenna will work much better with a lot of sheet metal under it.

Yes. I would say I’m getting lower than 1.1 SWR. Haha, it slams the needle! I was worried that the size would be a factor as well, but it hasn’t been. Haha, which is good, because I can’t physically separate the steel disc from the mag mount. Tried for 25 minutes, no dice.

Best,
D.

 

[Dwitherspoon]

Antenna performance is not all about the match, its how well it radiates. The match might seem ok with virtually no ground plane but the antenna will work much better with a lot of sheet metal under it.

I got the idea from a youtuber who was told over and over again about size and needing lots of metal, general surface area. Even some people telling him he needed an external wired ground for a magnetic mount! haha, so he proceeded to use a cookie sheet from the 70's. He got 1.2 SWR and ranges approaching 14 miles on AM, while doing the test in his basement.

Best,
D.

 

[prcguy]

That same guy might double his range with the same antenna sitting over a bunch of chicken wire or full size ground radials, etc. I'm not making things up, I've experienced what happens when you don't have enough ground plane and how it degrades your signal on both transmit and receive.

One of the last antennas I mapped out was a 43ft vertical on HF but it relates to CB. I started with just the 43ft whip and its mounting pipe in the ground. It kind of sucked to some people I had lined up for the test. Then I put down four 30ft long radials on the ground and it made a huge difference. Then eight radials and it improved noticeably but not as much as the first four. Then 12 and 24 and I stopped at about 30 or 32 radials, I forget but the improvements were getting very small at that point.

Going from just the 43ft whip and no radials to the 30 something I put down, on the other end of the radio you would think I turned on an amplifier. Its not a subtitle difference.

I got the idea from a youtuber who was told over and over again about size and needing lots of metal, general surface area. Even some people telling him he needed an external wired ground for a magnetic mount! haha, so he proceeded to use a cookie sheet from the 70's. He got 1.2 SWR and ranges approaching 14 miles on AM, while doing the test in his basement.

Best,
D.

 

[Dwitherspoon]

That same guy might double his range with the same antenna sitting over a bunch of chicken wire or full size ground radials, etc. I'm not making things up, I've experienced what happens when you don't have enough ground plane and how it degrades your signal on both transmit and receive.

One of the last antennas I mapped out was a 43ft vertical on HF but it relates to CB. I started with just the 43ft whip and its mounting pipe in the ground. It kind of sucked to some people I had lined up for the test. Then I put down four 30ft long radials on the ground and it made a huge difference. Then eight radials and it improved noticeably but not as much as the first four. Then 12 and 24 and I stopped at about 30 or 32 radials, I forget but the improvements were getting very small at that point.

Going from just the 43ft whip and no radials to the 30 something I put down, on the other end of the radio you would think I turned on an amplifier. Its not a subtitle difference.

I get that. I never said bigger wasn't better, bigger is always better as far as antennas and wattage is concerned. But a cookie sheet or 5 inch disc of metal works, and works very well and shouldn't be questioned or looked down on.

Best,
D.

 

[138BG]

bigger is always better as far as antennas and wattage is concerned. But a cookie sheet or 5 inch disc of metal works, and works very well and shouldn't be questioned or looked down on.

You might want to read up on some antenna theory if you actually believe that statement. Or just listen to Prcguy, don't think he started yesterday.