Maxtrac UHF capability question

[airboss]

My Maxtrac 300 is model D44MJA7JA5-K

My research shows that this model covers 403-430Mhz, 16 pin, 32 channels

I tested for receive and transmit - all OK (in the above range)

I retrieved the original code plug and archived it. Using the "repeater-builder.com" process - I programmed 10 frequencies from 440 - 449Mhz using the shift method (no problem). Saved it to the radio (no problem)

I tried adjusting the receive VCO (supposed to be voltage 2-7 volts). No change in the (test location) SL-1 voltage by adjusting the VCO coil. It stays at about 9 volts - on the 440 - 449 Mhz frequencies.

The radio does not seem to like being at standard ham 440 frequencies. Could not get it to work there.

I programmed the code plug back to original - works OK. Receive VCO is "approximately" back to original position.

Anyone have this model that have had success elevating it to 440? thanks

[PETNRDX]

What frequencies were in it originally?
That model number can be for either split of the radio.
Look at the number stamped on the RF board to find the original range.
Been awhile since working on a low split radio, but I would expect to see the RF board be HLE4424A for range one.
Later boards even had the range stenciled in white the actual split.And if you
My memory sucks, but there is a relationship between VCO voltage reading, and whether you are ABOVE or BELOW the radio range.
I "think" that if you have the radio programmed above range, the VCO should read low, and if you have the radio below range the VCO should read high.
Anybody else have better memory on that?

[airboss]

Model: 44MJA7JA5AK, 16 pin, 32 channels
Original code plug frequencies are 420 - 422 etc. I think the highest was 425Mhz.
RF board is HLE4424B
Logic board is HLN9313A
ROM ver 5.34

I didn;t see any article (on repeater-builder.com) about the low side of 440 band process. The only article I read was how to adjust the VCO, etc., from above the 440 band.

Like I stated - I can program it (using the shift method) to the 440+ frequencies, but receive VCO voltage reads high and does not change with adjustment.

Just wondering - does anyone have one of these that they successfully elevated to 440+?

thanks!

Alan C