MECTRON ME-400

[Smokinone]

Does anybody have any information on this radio? Other than a user manual I can't seem to find anything.
The one I have looks perfect, receives great, I haven't keyed it. I will save that for after a re-cap maybe.
Meishoh Electronics Co., Ltd. is the maker, and they also made LAKE CB radios, which are also elusive. Has a MSM5807 processor and is listed in Secret CB 17 for a channel conversion, but no alignment info.
Pictures are of the radio which I haven't done any cleaning other than the dust on the covers.

 

[saturated]

That is one nice looking radio

Amazing condition wow looks like it came out of a museum

 

[TM86]

Here's what I can find:

That may be from the user's manual so my apologies if it's redundant info.

If you decide to pop the PLL can off the board you could create the world's only known schematic for that part as well.

I'll say up front, I could be wrong about any or even all of these. Your radio, your comfort level with risk.

Taking a wild guess from the schematic:

RX chain adjustments - L1, L2, L3, L4, L5, L6, L7, L8.

TX chain adjustments - L9, L10, L11, L12, TC, L15, L17 (Not sure what TC's role here is).

VR1 - I'm stumped on this one. Might adjust the sensitivity of the first mixer stage?

VR2 - Signal level adjustment for "S" portion of S/"PF" meter.

VR3 - Squelch level or range

VR4 - Modulation? It's on the input to the audio amplification section after the speech compressor unit, so that's all I can come up with.

VR5 - AMC adjustment.

VR8 - Signal level adjustment for "PF" portion of S/"PF" meter. (Don't ask me why they called it that instead of S/RF.)

The pot labeled "DELTA TUNE" on the schematic - Yeah, that's it's purpose in life. Don't know if it's RX only or RX/TX. I think it's the pot just in front of the PLL can.

Sorry, I don't have any levels or frequencies to add.

 

[AudioShockwav]

Another very small tidbit that " might" be useful.
It's for the model number 402 so ......
Scroll down to page 41 for a pll mod
That's a rare breed

https://www.worldradiohistory.com/Archive-CB-Radio/Secret-CB/secret_cb_vol_14.pdf

( I linked to the whole thing in case it's useful to anyone)

73
Jeff

 

[Smokinone]

Here's what I can find:
View attachment 77048
That may be from the user's manual so my apologies if it's redundant info.

If you decide to pop the PLL can off the board you could create the world's only known schematic for that part as well.

I'll say up front, I could be wrong about any or even all of these. Your radio, your comfort level with risk.

Taking a wild guess from the schematic:

RX chain adjustments - L1, L2, L3, L4, L5, L6, L7, L8.

TX chain adjustments - L9, L10, L11, L12, TC, L15, L17 (Not sure what TC's role here is).

VR1 - I'm stumped on this one. Might adjust the sensitivity of the first mixer stage?

VR2 - Signal level adjustment for "S" portion of S/"PF" meter.

VR3 - Squelch level or range

VR4 - Modulation? It's on the input to the audio amplification section after the speech compressor unit, so that's all I can come up with.

VR5 - AMC adjustment.

VR8 - Signal level adjustment for "PF" portion of S/"PF" meter. (Don't ask me why they called it that instead of S/RF.)

The pot labeled "DELTA TUNE" on the schematic - Yeah, that's it's purpose in life. Don't know if it's RX only or RX/TX. I think it's the pot just in front of the PLL can.

Sorry, I don't have any levels or frequencies to add.

I didn't have the schematic so thanks for that.
As far as my skills, I can follow along fine with a service manual, some basic troubleshooting, but really have no formal training other than a basic electronics class I had in 1980...which was all book and no practical or lab...didn't really understand that.
Thanks

 

[Smokinone]

22 caps replaced. The 1000uf were spot on, but most of the smaller ones were higher than normal with higher vloss and ESR according to my T7 meter. No shorted or bad caps found.OSCAR branded.
Good receive as it had, keys up to about 3.5 watts and swings to 14 watts according to my WM-1.