Realistic TRC 450 Instruction Manual

[atombaum]

Does anyone have a source for a .PDF of the Instruction Manual (a.k.a. Owner's Manual) for the Realistic "TRC 450"? I see CBTRICKS.com has the Factory Service Manual.

Realistic TRC450 (21-1564)

Was there a separate Instruction Manual?

 

[sonoma]

radio shack carrys a lot of manuals but not this one. just checked for it.

RadioShack.com

 

[loosecannon]

atombaum,

just curious what you are trying to find out by looking in the manual?

or do you have a trc450 that you are trying to sell and want an owners manual to go with it?

we can probably tell you any info thats in that manual with regards to the radio's operation.
LC

 

[Lil'Yeshua]

.

 

[atombaum]

Thanks for the replies. Picking up a TRC 450 tomorrow, and wanted a copy of the manual to print. Not looking for any information in particular.

What is the difference between the TRC 450 and TRC 451? They look the same. Different chips? I "ASSuME" the TRC 450 came out first, but not sure. The schematics are available, so I guess I could scrutinize them to find out, but if anybody knows, I would appreciate it if they posted it here.

 

[ExitThirteen]

The TRC-450 is the single conversion MB8719 chassis, the TRC-451 is the D2824 chassis, two different breed of cats there. Hope this helps.


~Cheers~

 

[atombaum]

The TRC-450 is the single conversion MB8719 chassis, the TRC-451 is the D2824 chassis, two different breed of cats there. Hope this helps.


~Cheers~

It makes me curious. Is the TRC 451 dual conversion? I know what single and dual conversion is, but not MB8719 versus the D2824 chassis. Can you elaborate here? What are the pros and cons? Thanks.

 

[ExitThirteen]

The D2824 chassis is single conversion. The "single conversion" and "double conversion" applies only to AM mode. The dual conversion chassis is a little better for AM RX.

Most people prefer the MB8719 boards because they are more "extra channel" friendly. You can change the programming on the PLL directly thru the pins.

On the D2824 PLL, it's done in BCD ROM, and can't really be modified, however, they have a reference divider circuit out now (look up Galaxy "N" kit) that can allow channels thru the reference output pin of the PLL.

It's my personal taste, but I prefer the D2824 chassis, the NB/ANL circuit seems to be a little better designed, the AGC is nice and tight, responds well, and rock solid on TX frequency. But that's just my .02 worth.

The TRC-450 has a mic gain on it if memory serves me right, whereas the TRC-451 does not.

~Cheers~

 

[atombaum]

The D2824 chassis is single conversion. The "single conversion" and "double conversion" applies only to AM mode. The dual conversion chassis is a little better for AM RX.

Most people prefer the MB8719 boards because they are more "extra channel" friendly. You can change the programming on the PLL directly thru the pins.

On the D2824 PLL, it's done in BCD ROM, and can't really be modified, however, they have a reference divider circuit out now (look up Galaxy "N" kit) that can allow channels thru the reference output pin of the PLL.

It's my personal taste, but I prefer the D2824 chassis, the NB/ANL circuit seems to be a little better designed, the AGC is nice and tight, responds well, and rock solid on TX frequency. But that's just my .02 worth.

The TRC-450 has a mic gain on it if memory serves me right, whereas the TRC-451 does not.

~Cheers~

OK, so the TRC 450 (MB8719 chassis) and TRC 451 (D2824 chassis) are both single conversion by the sounds of it. Thanks for the info.

I think I'll move forward on the purchase of the TRC 450. It's supposedly never been out of the original plastic in the box. Photos seem to verify this claim (includes yellowed Scotch tape on the bags). I'm hoping this is a good thing. I'll bring it up slow on a Variac.

 

[atombaum]

I think I'll move forward on the purchase of the TRC 450. It's supposedly never been out of the original plastic in the box. Photos seem to verify this claim (includes yellowed Scotch tape on the bags). I'm hoping this is a good thing. I'll bring it up slow on a Variac.

Just to tie the ribbons on this thread - the radio turned out to be in NOS (new) condition as advertised. It is fully functional, and there were no surprises. The only negative was that it took eight hours of driving (round trip - all highway) to get it.

 

[w9cll]

Congrats on the new radio

 

[loosecannon]

the TRC450 is a good radio, and it does have a single conversion AM receiver, which means it has one less stage of "filtering" than the TRC451 would have.

not a huge deal, but worth knowing.

you will find that the trc450 comes with the MB8734 chip in it, and not the MB8719.
this means you wont get much "extra channel" capability from it unless you change the PLL to the MB8719. its a drop in replacement, but they are hard to find and expensive.
(MMB8719, and RCI8719 are similar but not exactly the same)

if you want to run this radio as your main radio, i would consider doing a re-cap job on it. that means replacing all the electrolytic capacitors and then doing a full alignment.

who knows, it may work fine for a long time, but the radio is old, and the caps do dry out, which can lead to a lot of head scratching when weird problems crop up.

hope you enjoy it,
LC

 

[Lil'Yeshua]

There's a 448 on ebay
Looks like new

 

[loosecannon]

those 448's are cool looking radios, and can do some extra channels, but man what a pain in the ass to work on!

have you seen the parts density in those radios? its tough to get the probes on the right part without touching another.

if i could buy one brand new, i would get another one. the large meter did look cool.
LC

 

[atombaum]

TRC-450 selectivity

This page from the 1980 Radio Shack catalog says the TRC-450 is dual conversion (two IF frequency stages)...

1980 Radio Shack Catalog Low-res page 81 of 176