399 JJ - Mods-for-Upd858-Chassis

[jrd426]

I remember finding this years ago probably before i joined the site and group here. I was thinking about it tonight and did have a hard time finding it again but wanted to share this and happy its still out there hehe. I guess he loved to help and share the info.



not sure how long it will be there but was happy to find the info and web reference again 73
Jeff

 

[TM86]

Good find!

Edit, attached as a PDF so that not everybody who wants a copy has to log in to scribd.

 

[rixdafix]

I stumbled onto that document a few months ago when I was recapping and troubleshooting my TRC458. I had heard it was out there and felt like I found a lost treasure when I saw it. Saved on 3 devices...

 

[Ghetto]

Thanks, I managed to save his website using the internet archive past snapshots but this PDF is more convenient. The legacy of unit 399 will live on forever and we will always remember him for his work on the 858 chassis.

 

[Ghetto]

After comparing the PDF to my HTML copy I realized the HTML version is better formatted and slightly more complete (not cut off on end of pages). You have to unzip to a directory and then open the local HTML page "HOME _ 858ssb.htm"

 

[guitar_199]

I stumbled onto that document a few months ago when I was recapping and troubleshooting my TRC458. I had heard it was out there and felt like I found a lost treasure when I saw it. Saved on 3 devices...

You aren't kidding!!!!!!! I have actually downloaded it several times.... and squirreled it away in several different places!!!!!!!!

If I am remembering right.... there is a place in there in one of the audio circuits that he claims ONLY the R/S TRC-458 replaced a diode with a resistor... and it limits modulation audio. He suggests putting a diode in to correct that!

Do you recall seeing that... and if so... did you make that change???

Just curious....

 

[doffo]

You aren't kidding!!!!!!! I have actually downloaded it several times.... and squirreled it away in several different places!!!!!!!!

If I am remembering right.... there is a place in there in one of the audio circuits that he claims ONLY the R/S TRC-458 replaced a diode with a resistor... and it limits modulation audio. He suggests putting a diode in to correct that!

Do you recall seeing that... and if so... did you make that change???

Just curious....

Now I am curious about this.... As I now have a TRC-458 sitting on my desk in front of me... It sounded ok on the air I suppose but now that has me wondering.

Did the TRC-449 fall the same fate?!?!

 

[MKwrench]

Now I am curious about this.... As I now have a TRC-458 sitting on my desk in front of me... It sounded ok on the air I suppose but now that has me wondering.

Did the TRC-449 fall the same fate?!?!

The 449 is the same. As an experiment, I changed C69 to 1uf tant, C77 & C78 to .47uf, C87 to 10uf, and R220 (in the D23 spot) to a 1N4148 diode. That should open things up a little, but it's hard to tell if its all in my head or not on my monitor radio. On air, I get reports of great sounding audio, but only after asking.... I dont want to be that annoying guy always asking: "Hows this sound?"... "Hows that sound?" LOL
I have that TRC449 in my truck, right now.

 

[MKwrench]

Theres a similar page on the 010 chassis by 399, floating around out there too. https://senorjj399.wixsite.com/the-pb-010-chassis
Not trying to steer off topic. He was relly cool for sharing his documented notes with the world.

 

[TM86]

Archive of https://senorjj399.wixsite.com/the-pb-010-chassis. Don't know how much longer it will be up so figured might as well grab it while it's still available. If anyone wants to clean the extraneous crap out of the file and repost, go for it.