VEX radio rx question

[g2tiger]

Hello all,

UPDATE: I originally posted in the scrap yard by mistake. Also, I did find some information on the radio system. so the updated question is what receiver is the most commonly used or recommended for the radio? See below for the original question.


I have a VEX radio transmitter that I need a receiver for. I have a channel 65 tx crystal in the radio and a set of 4 each tx/rx crystals (different freqs/channels) in a package, but no receiver. I have had no luck locating a receiver for the radio, but then again I don't know much about the VEX radio system. Is there some sort of information about the radio that I can get that will give me a better understanding of the radio and receiver that anyone can recommend? My web searches are not yielding much. The VEX website appears to not have any or much on the specific radio we use for controlling the subs.

Since I have a working complete radio and receiver set for a different model and the receiver for that set looks like most all receivers I am curious if I can substitute a different receiver with the ch 65 rx crystal. Any guidance would be appreciated.

[neitosub]

Hello all,

UPDATE: I originally posted in the scrap yard by mistake. Also, I did find some information on the radio system. so the updated question is what receiver is the most commonly used or recommended for the radio? See below for the original question.


I have a VEX radio transmitter that I need a receiver for. I have a channel 65 tx crystal in the radio and a set of 4 each tx/rx crystals (different freqs/channels) in a package, but no receiver. I have had no luck locating a receiver for the radio, but then again I don't know much about the VEX radio system. Is there some sort of information about the radio that I can get that will give me a better understanding of the radio and receiver that anyone can recommend? My web searches are not yielding much. The VEX website appears to not have any or much on the specific radio we use for controlling the subs.

Since I have a working complete radio and receiver set for a different model and the receiver for that set looks like most all receivers I am curious if I can substitute a different receiver with the ch 65 rx crystal. Any guidance would be appreciated.

If I recall, I’ve tested my Vex radio with a Futaba R127DF receiver on 75mhz (by inserting in the Vex Rx crystal that came with the radio) and it worked. The other receiver I’ve gotten to work with the radio is the Novak Synthesized XXX 5-ch receivers, but these are hard to find. I have a feeling these Vex radios are somewhat rebadged Futaba 6EXA systems, they have very similar button layouts and menu navigation, if you have a spare Futaba 75mhz receiver laying around, it might work.

Nate

[g2tiger]

Neitosub,

Thanks for the quick response. I think I do have a 6 ch Futuba rx lying around. I'll check after work tonight, it would be great if it worked.

Charlie

[cheapsub]

For what I know and tested.

The RX crystal in the set is a single conversion crystal. So the Futaba FP-r127df will not works with the crystal, it's a dual conversion RX.

all FM 75MHz and most (not all, short answer)72MHz negative shift will works with VEX / Futaba transmitter.
As long as it has the matching frequency crystal, single or dual conversion.

So all futaba, hitec(dual conversion) and some Chinese rx may works.

Small good news, all brand dual conversion RX crystal are exchangeable. airtronics, futaba, hitec same!
BUT not single conversion, hitec FM single RX use AM crystal!


Bad news, (I am a half empty person)

is very hard to find a matching frequency crystal.
the rx crystal that came with the sets are single conversion.
Single conversion receiver mostly comes in 3 ch mainly for cars.
and the pins always pointed up, the wrong way.

These are the receivers that works with the crystal that comes with the sets.
l know they are all 72MHz, tested they work.

[cheapsub]

Work around the long story.

match up more RX crystal. ( Single or dual conversion )
Make a TX crystal (futaba or compatible) adopter .


replace the crystal socket on the TX.


can't find any small RX that
no soldering works around and all the pins pointed sideways, get a JR receiver!
Is that JR RX is positive shift!
I Tested it works.
For reason I do not know. When you install a JR 75MHz crystal (matching frequency), it will turn it into a negative shift RX.
note: on the "universal RX" set it to positive shift.

[E-sky is for size reference]

The Chinese one now is hard to find.
But a lot of JR could find in used market, some time it came new in the box.

The crystal is another story, good luck.

[cheapsub]

I have a feeling these Vex radios are somewhat rebadged Futaba 6EXA systems, they have very similar button layouts and menu navigation,

Nate

Check out my post, ungoofy VEX transmitter post.
Just add two 3 position switches.
the PWB are the same size.