Cobra cam 89 frequency mod?

[Robotto]

I have a Cobra cam 89. It has 23 channels. I am trying to talk on channel 28-40. Is there any way that I can modify the unit to work on these channels? If I lose the lower channels it.is all good. Thank you in advance for your time.

[Bozo]

Model 89_064349.png

I have a Cobra cam 89. It has 23 channels. I am trying to talk on channel 28-40. Is there any way that I can modify the unit to work on these channels? If I lose the lower channels it.is all good. Thank you in advance for your time.

Hey @Robotto,

Welcome to the forum and great to see you on here!

The Cobra Cam 89 is a classic rig — solid build and nice audio. Since it only covers the original 23 FCC channels, getting it to transmit on channels 28–40 (which are part of the modern 40-channel band) would require a modification to the PLL (Phase Locked Loop) circuit.

Depending on the PLL chip used (likely a uPD858 or similar), you might be able to expand or shift the frequency range with crystal swaps or a channel mod kit. However, this is not a beginner-level mod — it often involves removing or replacing crystals, cutting traces, and adding switches or jumpers.

If you're okay losing the lower channels and just want the higher ones, a crystal swap might get you close to 28–40. But the exact steps will depend on the board and PLL chip inside your unit.

A few tips:

• Check the PLL chip number on the board to know what's possible.
• Search for a SAMS Photofact or service manual for the Cobra Cam 89 to get a schematic.
• Consider finding a mod guide for your specific model or similar radios.
• Be cautious — transmitting on unauthorized frequencies or making unshielded mods can cause interference and get you in hot water with the FCC.

If you’re not comfortable with board-level mods, sometimes it’s easier (and safer) to pick up a used 40-channel radio that already has those channels available.

Hope this helps, and keep us posted on your project!

73s,
Bozo

[Robotto]

Thank you much