• 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.

Can a radioshack trc 55 be modded for xtra channels?

Rwb

tell the devil im gettin there as fast as i can,r
Jun 30, 2018
3,809
5,043
523
69
I got a trc 55 handed to me.it was dead in the water. Took 5 minutes to find the culprit.
Its only a 23 channel, would like it to be 40 or more channels.
Hope somebody can answer up,not leave me in suspence
 

Rwb,
Using the attachment provided by Lou Franklin, you can swap 1 or all of the 33.xxx Mhz crystals to extend the frequency/channel range of the TRC-55. Not sure if there is a Siltronix VFO whose oscillator is near the 33 Mhz range.

73
David
 

Attachments

  • trc55mixingscheme.pdf
    20.6 KB · Views: 12
  • Like
Reactions: Rwb
Rwb,
Using the attachment provided by Lou Franklin, you can swap 1 or all of the 33.xxx Mhz crystals to extend the frequency/channel range of the TRC-55. Not sure if there is a Siltronix VFO whose oscillator is near the 33 Mhz range.

73
David
so no cut wire change locations add switch?
 
Rwb,
It's not a kit.

Example:
Replace the crystal associated with Ch. 1-4 from a 33.000Mhz to 33.440Mhz and your new frequencies for channel position 1 thru 4 will be:
Channel 1 =27.405
Channel 2 =27.415
Channel 3 =27.425
Channel 4 =27.445 (because of the channel 3A skip in the selector)

Looking at the mixing scheme, find the frequency you want to use and add the value of the column "C" mixing crystal to that frequency to find what new crystal you will need for that frequency. Each added or substituted crystal will affect 4 different channel selector positions except for positions 21-23.

73
David
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ Wildcat27:
    Hello I have a old school 2950 receives great on all modes and transmits great on AM but no transmit on SSB. Does anyone have any idea?
  • @ ButtFuzz:
    Good evening from Sunny Salem! What’s shaking?
  • dxBot:
    63Sprint has left the room.