Ham Radio Project?

[dogman]

For some years I have wanted to join the Ham Radio community, today I was given a Trio jr-200 communications receiver an old valve receiver.
I have attached a picture of it & wanted to know as a restoration project would this make a suitable receiver once restored?
I removed the bottom cover & all the hard wiring & components actually look like new, very clean.
The outer cover has some small surface rust in sections but overall it looks like a project?
Obviously everything needs to be checked out before plugging in etc.

Is it worth restoring, I would like to use something I have restored myself.

 

[rjenkinsgb]

It's definitely worth a go!

 

[danadak]

1) Look at plate and cathode R's, they can be out of spec significantly.

2) Get rid of/replace all black beauty caps if present :

3) Clean band switch, preferably with DeOxit or alcohol.

4) Check all V's and R checks in radio from manual tables of same.

5) Obviously tube checks if you can get your hands on a tube tester.

6) Any solder joints to chassis ground, check with a magnifying glass that
soldering good.

7) Screws and nuts on shields' to chassis retighten.

8) Very careful if doing IF alignments, use non metallic tools. And if stuck
use a hair dryer to heat up IF can/coil to loosen up tuning slug. Slugs
can be sticky from wax used in coils to keep slug from moving after
adjustment. Bamboo kaboob sticks using xacto knife can make good tuning
tools.


Regards, Dana.

 

[dogman]

1) Look at plate and cathode R's, they can be out of spec significantly.

Resistors out of spec from manufacturer or ageing?

8) Very careful if doing IF alignments

Do you know where I can find IF alignment values & procedure for this receiver?

 

[danadak]

Usually in the old tube receivers that is in the user manual. Or Service manual if that
had one.

JR-200 Amateur-R Kenwood, Trio-Kenwood Inc.; Komagane, build 1966 ? |Radiomuseum.org

JR-200 Amateur-R Kenwood, Trio-Kenwood Inc.; Komagane, build 1966 ?, 4 pictures, 1 schematics, 7 tubes, Japan, semiconductors, Amateur-Receiver (amateur bands

www.radiomuseum.org

R's out spec from aging, moisture absorption over time, heat....


Regards, Dana.

 

[dogman]

Usually in the old tube receivers that is in the user manual. Or Service manual if that
had one.

Thanks for that, I'll have to find a manual or get some information about it.

 

[danadak]

Trio Kenwood JR-200 Tech Specifications Schematic Original 1968 The Real Thing | eBay

Find many great new & used options and get the best deals for Trio Kenwood JR-200 Tech Specifications Schematic Original 1968 The Real Thing at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[danadak]

There is only two IFs to adjust, so simple method tune in a weak signal,
turn off AGC, and adjust them for max audio. You should only have to
do this for less than one turn of slug. Remember where the slug is when
you start, just in case there is a problem and you put more turns on it
and need to restore to original position.

 

[dogman]

danadak​

Thanks for the info, I found the schematic on the radio museum site, I also found that another receiver a "lafayette_ha-63a_communications_receiver" from the same manufacturer as Trio has a near identical circuit layout.
I was able to find a service manual for the Lafayette & it has IF alignment, BFO Adjustment & RF Alignment procedures & specifications & a nice clear schematic.
Very clear & precise document so I should be good to go.