Crystal/reciever help
 

Hope someone can help, I have rang Mirage and A few other places with no avail.
Ok here goes.

I have just setup a new car. I have had the Agressor CRX transmitter by Hitec for a month now and love it. It came with a duel convertion DCX FM (40) reciever. My old car has been working a treat.
I want to run the new car with the same transmitter but a different crystal.
I was given 2 x Hitec HFS-03MM (40) FM recievers from a friend who got them with transmitters but didnt use them. neither worked with the Nosram missile power ESC. I tried the DCX from the old car, and all worked well. I guessed the new recievers must be duff so sent off for a nosram Gemini reciever.... When it arrived i installed it, double checked the colour of cables ect and same problem....

Im not to up on the difference between duel and single convertion, the DCX and the other two recievers have deep holes, the nosram has a shallow hole.... (question 1 is there a difference in size of crystal when duel and single conversion or is it just a size difference between TX and RX).

Another friend gave me a KO PROPO KR-297FZ reciever and a Hitech Flash 4 pro car transmitter. I popped in the reciever and all worked well using the Flash 4 transmitter.. Swapped the KO PROPO for the Gemini and switched crystals..... Again nothing..

Put the crystal from the Ko Propo (40.875) into the HiTec HFS-03MM and nothing... (Friend says both HFS-03MM have NEVER been used)

The crystal in the Aggressor CRX is a channel 50 duel conversion.
The crystal in the Flash 4 is a channel 85 (unknown conversion).
All recivers and transmitters used in this are FM (40).


Can ANYONE shed any light to why im getting such vast compatibility problems???

Shark

I am only aware of dual conversion crystals and recievers being used in aircraft so over hear that would be 35meg and not the 40meg from your previous radio?

Also Pictures tell a thousand words if you could post some it would help

ok some links.

Hitec Agressor crx

Hitec HFS 03mm Reciever

Hitec Flash 4 Pro-car transmitter

Info on duel conversion being used for cars.

Hitec DCX

Dual-conversion receivers have been used in the RC airplane hobby for years; now Hitec has brought that technology into the RC car hobby.

A dual-conversion receiver sends the signal through two filters instead of one, and this provides better reception with less interference-that's especially helpful for gas racers. Only Hitec's receiver crystals can be used in this receiver, and it's on the large side, but the extra security of two filters makes up for these inconveniences. Two versions of the DCX are offered: one for JR, Airtronics and KO radios and another for Futaba and Hitec units.

If you are saying that the recievers that your freind gave you are the same as the one you are currently using in your old car then you really should have no problems using the same crystals that you are using in your old car.

I do know that dual conversion crystals are different though and you need to use a dual conversion crystal with that type of reciever.

Check the recievers one at at time with the radio that you want to use and just make sure that you have the correct type of crystal for the reciever and check with hitec that you can use these other recievers with your radio.

Ok after some resurch i know i cant use duel convertion crystals in a single con reciever.

So i used the crystals that worked in the Flash4 - KO propo setup (that worked) in the gemini reciever, and it didnt work.
I also tried them in the HFS-03MM and they also didnt work.


AAAAAAAAAAAAAAAAHGH

I have read somewhere that Hi-Tech transmitters are on a different shift.
Can anyone explain this?

Does this mean that even though the KOPROPO worked, it may be badly filtered and picking up bleed over from this shift. The Gemini being a better reciever and better filtering means its not picking up shift, and will need a 100 matched crystal.

?
Hmmmm

Hitec/xtal issue
 

Hello,

Are you using a K.O. Fet servo that does not have the additional blue power wire and/or an AMB personal transponder?

I couldn't tell from the Hitec catalogue, but is the CRX PPM/PCM switchable?

K.O. xtals work in Hitec single conversion and Nosram Gemini receivers.

regards,

Damunn