Okay, so I bought a Polk's Tracker III with no receiver for my Ark Model Type VII WTC. So I find a nice, but overpriced, six channel receiver on eBay, but I am asked whether the transmitter is a positive or negative shift transmitter. Who knows? I don't and neither does the seller. Next up on the confusion factor is the crystal. I need a crystal for the receiver As it is not included. Again I find there is a positive and negative shift factor involved with the crystal. Not sure what the crystal situation is with the transmitter. One thing is certain, when it comes to 75 MHZ there is no such thing as plug and play. So how do I set up my Tracker III with a proper receiver and crystal. All guesses will be considered. "I finally put my oar over my shoulder and headed inland looking for questions. "
https://www.rc-submarines.net/programming-the-polk-tracker-iii.html https://www.rcuniverse.com/forum/beginners-85/4610699-polks-tracker-iii-radio.html It seems that the Tx has no crystal and can channel hop but needs to be properly programmed. Also works with any crystal shift.