Changing bandwidth on Sennheiser G2 Tx unit

[Nicktaylor]

Although most of my kit is Sennheiser G3 sets of radiomics I have also got channel 70 stuff as a back up for higher numbers required on a job. I just bought used G2 beltpack which is marked 833-866Mhz but on powerup is 518-554Mhz with no means of tuning outside that. It was a cheapish Ebay purchase from a seller of lots of things. Is it possible a previous owner has recycled a case and therefore its actually a Band A device? Is the re any way of tuning higher?

[kgallen]

Sounds like the RF board from a Band A device fitted into a Band E case.

The electronics is designed to operate over 36MHz of bandwidth, that is the specified limits of the circuit. The circuit is tuned for the Band required - the specific R and C values are tabulated in the Service Manual. In addition, there is an EEPROM on the RF board that tabulates the frequency choices that the microcontroller presents on the UI and uses to programme the PLL on the RF board.

To change the band you would have to swap the relevant Rs and Cs on the RF board (some very small SMD components under RF shields) and reprogram the EEPROM. The former may be viable if you have SMD rework capabilities. The latter is more tricky unless someone can share the Sennheiser service software for G2. I've consistently failed to find it on t'net (so would be grateful if anyone can share!).

ETA: Apologies I'm actually talking with knowledge of the RX here, but I believe the equivalent applies to the TX.

Edited September 13, 2022 by kgallen

[Nicktaylor]

I thought it would be something like that . Probably better I sell it to someone with the correct licence! Thanks for the comprehensive answer. 

[boswell]

We use band A, how much??