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Realistic TRC-460

T

TiP

Member
Apr 1, 2008
5
0
11
I think we've got another one of those "mystery radios" on our hands. I was able to find a parts list on this radio, but no schematic, no tuning information, nothing to really go on.

Does anyone have any info on this radio? It's one of those "emergency-type" CB-with-weatherband-reception deals, except that I replaced the weak stock antenna with a center-loaded one from an older 3-channel handheld that's quite long.

I'm planning to co-opt the redundant channel-9 switch to something like the famed "Cobra-29-type-RX-improvement-mod" with pin 14 of the PLL and the positive side of C12, but I'll need the schematic to work it out.

Does anyone have any info?
 

No, I really am serious.

EDIT: Forgot to reinstate the call for information. I really do need that info.
 
tip,

the reason you cant find any mod info on that radio is because it is not worth modding.
that is a throw away radio meant to be put in the trunk of a soccer mom's SUV, and used futily one time in 10 years.

there is nothing that you are going to do to that radio that will make it get out even 100 feet further than it does now, and even if you did find the modulation limiter, you would only make it sound worse.

the fact that you think that the 29LTD receive mod has anything at all to do with this radio, and that looking at a schematic would somehow help you shows how little you know about this stuff.

im not trying to be mean, but you really shouldnt be messing around inside that, or any other radio until you learn a bit about what you are actually doing in there.

you wont find a shop in the country that thinks that radio is worth fixing if it breaks.

time to go buy yourself a 29LTD and start doing some reading.
LC

geez, i coulda swore you were kidding!LOL
 
Well, I know that the 29 receive mod isn't dependent on the PLL, but rather by applying voltage across to a capacitor in the 1st IF receive section, it desenses a detection diode which injects a lot more RF into the receiver. (I know it's not exactly like this, but it's been a long time since it was explained precisely to me.) The point I was trying to make is that the mod itself is rather simple, and should only involve isolating the correct pin on the PLL and the correct cap to jumper it to through the resistor/switch.

I know it's a weakie-squeakie B.S. radio, but there's no reason that it can't be used as a platform from which to forge a truly awe-inspiring handheld. I'm already planning to replace the final and driver, but again, without that schematic I'm screwed.(If only I could get ahold of a Cherokee AH-100. :( )

I would never clip the mod limiter on a radio. A friend of mine did it to a couple of radios, a Maxon MCB-30 and a Uniden PC-33, apparently because he was ready to write them off as trash. I wasn't, but it's clearly too late for those two. I know all about splatter and overmod, and I'm not looking to get myself into any situation involving those.

I have a ham liscence, and I'm not some ignorant backwater knownothing hick like you seem to think I am, but I would appreciate toning down the condescention next time. It's only an electronic circuit, and as such is subject to all sorts of manipulation, just as any other circuit is.

Now then, does anyone have any info?
 
Realistic

Contact Kens Electronics !! He will tell you what number SAMS PHOTOFAX manual that radio is in and he has them in stock for about $10.00 !!
 
I wouldn't call the 460 throw away trash. They are what they are. I would suggest a antenna adaptor (RCA I think it is ?) and use a good antenna and feedline on it. Wilson 1000/5000 (solid mount or magmount) would make a huge differance. (Maxon MCB-30 and a Uniden PC-33) are good loud radios , they can be tuned very nicely and weather or not the limiter is clipped in them or not ? stock mic or NC mic will work very nicely on them for mobile use anyway. (resistors can be put in line with the diodes to bring them to 100% if need be) I've seen little radios like that turn a few heads over the years , most have Uniden made boards in them and will put up a fight with the bigger boys everytime. (FEEDLINE AND ANTENNA is always a plus on any radio) :thumbup:
9443_1.JPG
 
tip,

you are definitely the exception to the rule here.
if you have been into radios for a while like you say, then you know as well as i do that 99.9% of the people who would ask for mod info for an emergency radio are completely new to the hobby, and had a buddy tell them that they could make their radio louder.

my statement was not meant to be a condescending statement to a knowledgeable person; it was meant to be a cautionary statement to someone that might end up smoking the only radio they owned.
thats why i said i wasnt trying to be mean.

if you are someone that is just in it for the challenge; i can respect that, although i still maintain that this is a throw away radio.

with that said:

there is not much info out there on this chassis, most likely because the manufacturer assumed that it would not be economically viable to have this radio repaired. thats why i use the term throw away radio; not because i think it doesnt work well, but because when it breaks, you just throw it away and buy another one. its like that with many consumer electronic devices these days.

this radio does not put out 5 watts.
that is input power.
it puts out 2.5 watts, and draws 1200mA at full modulation.

it uses the 2314 pre-driver, the 2075 driver, and the 2078 final.
i suppose this final could be made to put out more, but you'd have to use a wall wart, as i doubt the batteries would last long.

the PLL is a C5121, and its a ROM type chip, so freqs. are pretty much out of the question, unless of course you do the EPROM thing.

here are some other radios that use this PLL:
Cobra 19+(late), Colt 357A, Contact 40FM, Dick Smith D-1200, GE 3-5909A,
Intek M4035, Lear Jet, MCE 540, Midland 77-106/77-112/77-155/77-157,
Pace CB8001/CB8002, Regency info CB-1/CB-2, Unic RV-CB40TB

here is a link to a pinout of the PLL.
i dont see a buffered reference output pin, so im not sure if youre going to be able to do the pre amp mod.
not sure what "Rsft" stands for.
http://members.tripod.com/~malzev/comp/c5122.htm


good luck,
i really did think you were kidding.
LC
 
I AGREE WITH BOTH OF YA GUYS...TO A POINT i dont think the radio is a throw
away radio.but also think that the insides of these units should be left alone
also.these radios imho are unique cause there great when using a leased/rented
vehicle.or if ya dont wanna radio permantely in your vehicle then yes this is a way
to go.clearly this isnt a cobra 29 biut like switch said radio shack carries those adapters
get that and any external antenna with make a big improvment.also id use a cigerette
lighter adapter for power and not batteries
 
Realistig

I agree they are good little radios I use a GE help 3-5900A radio in my car hooked to LIL Wil antenna and plugged into cig lighter and it works and talks great no one believes me when I tell them what I am talking to them on!! :thumbup:
 
Last edited:
First of all, let me thank you all for yourwell thought-out posts.

After considering all your advice, as well as that of the locals around here, I've determined that the TRC-460 will NOT be the platform selected for this project. Its crippled output, combined with the overall lack of documentation, were high hurdles for this chassis to overcome. But the final nail in the coffin came when I opened the unit again, to get a clearer look at the finals; there's no silkscreen on the board in my unit! Now, I'm going to go out on a major limb here and say that I probably just got an f'ed up unit that got snuck past a sleeping QC worker, or maybe the manufacturer had a rush order on this lot and couldn't scrap any boards, or even maybe these radios were made in some offshore sweatshop of a factory with minimal (or nonexistent) QC. [Yes, I've worked in some big-name electronics manufacturing plants over the years.]

But for all of the aforementioned reasons, this handheld will most likely be dismantled for spare components, and the search for a better, more suitable handheld (like that Cherokeee AH100!) will continue.

As an aside to Loose Cannon: Your apology, such as it is, is warmly accepted; I think you and I could get along well if we ever had the chance to hang out.

For the rest: Thank you all for your input and advice on this issue. Sorry to have led you all down a dead end, but that's an important reason why we have these forums: to get useeful information before wasting boatloads of time on something useless, right? :)

Thanks to you all again,

Tip
 
Unnecessary Roughness; Foul

Tip, I was apalled as I read a response to your inquiry. Why all of that? I am interested in a 460. Its utility and low cost are attractive and fill my "meager" needs. I know little about CB and frankly don't care a great deal. I am, however, civil and do not push others until pushed. Then, it's rare indeed that the cyber hero will stand before flesh and blood. Right, bring yourself.
I have a hunch that the poroblem was a lack of fiber or a small shifter and large truck. Keep moving on, Sir.



TiP said:
Well, I know that the 29 receive mod isn't dependent on the PLL, but rather by applying voltage across to a capacitor in the 1st IF receive section, it desenses a detection diode which injects a lot more RF into the receiver. (I know it's not exactly like this, but it's been a long time since it was explained precisely to me.) The point I was trying to make is that the mod itself is rather simple, and should only involve isolating the correct pin on the PLL and the correct cap to jumper it to through the resistor/switch.

I know it's a weakie-squeakie B.S. radio, but there's no reason that it can't be used as a platform from which to forge a truly awe-inspiring handheld. I'm already planning to replace the final and driver, but again, without that schematic I'm screwed.(If only I could get ahold of a Cherokee AH-100. :( )

I would never clip the mod limiter on a radio. A friend of mine did it to a couple of radios, a Maxon MCB-30 and a Uniden PC-33, apparently because he was ready to write them off as trash. I wasn't, but it's clearly too late for those two. I know all about splatter and overmod, and I'm not looking to get myself into any situation involving those.

I have a ham liscence, and I'm not some ignorant backwater knownothing hick like you seem to think I am, but I would appreciate toning down the condescention next time. It's only an electronic circuit, and as such is subject to all sorts of manipulation, just as any other circuit is.

Now then, does anyone have any info?
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