UHF wireless Microphone frequency problem

[Teun]

Hi I'm new to the forum. We have a sewin pp2200 amplifier for cd and microphone(s). Also wireless. The problem is

that the receiver is 794.625 MHz and the mic is 812.800 MHz. The receiving unit has 3 adjustable parts. Can someone help us?

Thanks in advance, Teun

 

[Nigel Goodwin]

Assuming it's not a synthesised receiver (or transmitter) you would probably only have to change one of the crystals, there might not be any retuning required, as they are fairly close already (and might have been aligned to quote with different crystals at the factory anyway).

I'm presuming the picture is the receiver board?, and the crystal is probably the one at the far left - the one in the middle/bottom is most likely the 2nd conversion oscillator which is a fixed value.

 

[JimB]

My best guess is that to change from 794 to 812Mhz, you will have to replace the three filters and the crystal which I have marked on the picture.

This frequency change is not as simple a turning a few inductor cores.

JimB