• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Click here to find out how to win free radios from Retevis!

picture of 858 pll extra channel mod.

Carl

Technologicaly Challenged
May 7, 2005
895
27
28
44
working on a 139xlr and I can't get it to accept extras for the life of me. anyone have a picture of a ssb 858 chassis (trace side) so I can make sure I'm doing the right pins.

Sent from my SAMSUNG-SGH-I997 using Xparent Blue Tapatalk 2
 

see if this link will help you do it.


Realistic TRC-458 26.045 to 30mhz expansion


The thread is not that old.

The wayback machine does not have a copy of the webpage link posted above.

I have a working Trc457 Navaho that I just recapped and aligned.

I would like to expand the frequency coverage. 80 up 40 down without buying an expensive kit if at all possible.

Maybe the original poster copied the web page ?

Best 73s John
 

Hi 399,

Thanks for taking the time to post the Links.

I actually found the first one after posting here.

The web page author states raising the Trc 457 power Supply to 14.8 Volts ?

Has to be a misprint.

The original 3300uf in my Trc 457 was Bulging. I replaced with 5 x 1000 uf. All I had new.
Replaced the small one with a new 220 UF. When I get my order will re-replace with Low leakage 125c 4700 mfd.

Did the 15uf & diode swap.

Did the Shotky swap.

I am not satisfied with the modulation percentage average Only %60 peak 70.

What about this Mod from a Defpom page. Will this perhaps get this close to 100% modulation.
As an SSB rig. I will not chop out the AM limiter.
_________________________________________________________
(Mike circuit changes:)
1. UNSOLDER banded end of diode D21 and lift up.
2. UNSOLDER banded end of diode D22 and lift up.
3. SOLDER a 4.7 k resistor across where D21 and D22 was unsoldered.
4. Replace R78 (27k) with a 56k.
5. Replace R84 (4.7k) with a 2.2k.
__________________________________________________________
Would it make a difference if I swap out 2SC1419 to a NTE 152? & Or swap the
upC1156H & replace with Toshiba TA7222AP
__________________________________________________________
For the extras what about this. Just received the RS switch.

This is from Secret CB Vollume 9 page 8-11 Hosted by CB tricks You can download the complete PDF. upd 858 rotary switch expansion
__________________________________________________________
upload_2015-1-11_20-44-21.png
upload_2015-1-11_20-45-49.pngupload_2015-1-11_20-47-40.png
 
Not a misprint. 14.8 is good. The defcom mod will eliminate the speech clipper circuit and will actually reduce average modulation.
 
Last edited:

dxChat
Help Users
  • No one is chatting at the moment.
  • @ BJ radionut:
    EVAN/Crawdad :love: ...runna pile-up on 6m SSB(y) W4AXW in the air
    +1
  • @ Crawdad:
    One of the few times my tiny station gets heard on 6m!:D
  • @ Galanary:
    anyone out here familiar with the Icom IC-7300 mods
  • @ Crawdad:
    7300 very nice radio, what's to hack?