I have KO Propo Precious Ex-1 TX and a HFS-03MT rx. Do I use KO Propo or Hitec crystals with this setup? I currently have Futaba ch82 crystals and all I get is glitching.

For this setup use KO's single conversion receiver crystal in the receiver.

thank you

In general should you use the brand of crystal that matches your transmitter not your receiver? (and make sure if it is dual conversion to use that crystal on the receiver.

I picked up a Hitec HFS-03MM off EBAY, it did not work with my Airtronics using the Hitec crystals it came with I assume I need the Airtronics crystals.

When using a single conversion receiver, yes match the receiver crystal to the transmitter manufacturer. When using a dual conversion receiver match the crystal to the receiver manufacturer.

So for your 03mm receiver and Airtronics transmitter, use the Airtronics single conversion receiver crystal in the receiver.

Well I tried a KO crystal set as you instructed, but with no luck. I even tried another receiver with the KO radio. The radio has a RF-102F FM module in it which according to everything I have read is a 75 mhz module. So far I have tried two different rx's. One hitec and one futaba with the same results. They both glitch and do not respond to the tx at all. I have sent an email to KO for advice and am waiting for a response. In the meantime I still have the hitec rx. Is there anything else I can try to make this thing work before I send it back?

Could this KO radio possibly be a PCM radio and not FM?

Please forgive my ignorance, but what is pcm?

Ok I googled it. This is a ppm radio. It says so just below the LCD display.

"PPM 1024 Steps Resolution"

Can you confirm that the frequency crystal in the module of the transmitter is the correct crystal for that module/transmitter setup?
If it is correct then the transmitter should be working with the receiver. Do you know that this transmitter even works properly? Do you have the KO receiver to test the transmitter with? There could be a problem with the transmitter not putting out anf RF in which case you need to sent the radio to KO to have them check it out.

Yes, it is a KO Propo single conversion crystal set

It worked perfectly before I swapped the rx into another car and shorted it out when plugging in a battery pack wired for futaba. It was an airtronics rx.

No I do not have a KO receiver and I don't want to spend over 100 dollars to get one for a 10 year old radio. A friend of mine has a FM frequency scanner which will show what frequencies are in use. I can test the tx with that to see if it is working. I will keep you posted. Thanks.

The transmitter side does not use a single or dual conversion crystal. It will be a specific transmitter crystal which is different from a receiver crystal. Do you have the original Tx crystal still in the transmitter? If it has ever been removed it could be possable you placed a receiver crystal into the transmitter module by accident. Pull the crystal out and double check that it is a transmitter crystal in there and not a receiver crystal. You may need to check with KO for the markings on their crystals but usually it is stamped with TX somewhere on there.

I replaced the original crystals because I had lost the rx side and had no idea what freq it was because it was not marked on the crystal. The new crystal which is marked TX is the one that is currently in the transmitter.

And this is a KO crystal right?

yes