I have a new Multiplex Profi Car 403 transmitter that is able to transmit both AM and FM using the Multiplex transmitter crystals. I am looking for a compatible FM receiver and am considering the Hitec HFS03MC. I have Multiplex brand transmitter crystals on channels 67, 70, 80 & 81.

Can you tell me if this receiver with a matching Hitec single conversion receiver crystal will work with my transmitter?

Steve

Good question, I honestly don't know if it would work or not. I have had no exposure to the Profi at all. No one around here has one. What you could do is see if your LHS would let you try out the combo at the store before you buy anything. TTYL.

Gary F, Team Hitec.

Gary;

Well, I will soon find out as I now have the receiver I mentioned above and 5 receiver crystals are on their way that match my profi Tx crystals. The folks at Multiplex USA have indicated that all will be fine as have the folks at Multiplex UK so I feel pretty confident. I will advise.

... any on your receiver line is compatible with M8? mine is 40mhz FM ...

SteveM: did Multiplex tell you that you had to have the shift changed on the radio in order for it to work with the Hitec receiver? My nephew has Futaba equipment, which I believe is on the same shift as Hitec and he was told that he should have it adjusted over to that shift in order for it to work! It is normally set up to the shift that Airtronics, Ko, and JR are on! Let me know how it works out for you and whether or not you did have it switched over, it would be greatly appreciated! I have been wondering if this adjustment is really necessary, being that it isn't free or cheap!

Stik, If you are in North America, we don't have any receivers that would work for you. We only have 75mHz and 27mHz frequencies here. I'll check into availability of other frequencies over seas for you tho. TTYL.


Gary F, Team Hitec.

I now have all the items I need to test out whether a receiver from Hitec will work with my Multiplex Profi Car 403 transmitter. To set the stage, here is my test equipment setup;

Transmitter = Multiplex Profi Car 403
Tx Crystals = Multiplex brand, Channels 67, 70, 80 & 81
Receiver = Hitec HFS-03MC Single Conversion FM surface 75mHz
Rx Crystals = Hitec brand Channels 67, 70, 80 & 81. All receiver crystals are 75mHz FM single conversion receiver crystals. PN-6687567, PN-6687570, PN-6687580, PN-6687581
Servo = HPI SX-1 with Airtronics Z connector (same as JR and Hitec) Basically a 94201 servo with a new label from HPI.

I plug the servo into CH1 on the receiver, insert Rx crystal on channel 70, leave Tx crystal channel 70 in the transmitter, select the menu on the Profi 403 and change to FM modulation, plug in a 4-cell receiver battery pack. Leave the Tx turned on and then turn on the power from the receiver pack.

Results = NOTHING.

Now what?

I have heard that the shift on the profi is selectable. Make sure that it is on a negative shift for Futaba/Hitec.


Gary F.

Gary and SteveM: Unless I am wrong, the only way to change the shift on the Radio is to send it in to Multiplex! This is what my nephew had to do, actually he purchased from them so he had it done before it was shipped. You can't adjust the shift on the radio itself, it has to be done by some techs. SteveM, call Multiplex and see what they have to say. It looks as though they weren't BSing about the shift change, lol.

SteveM: If you can,try some of the same brand crystals in the radio, the hitec ones. If that doesn't work you will most definately have to send it in. The guy I talked to, I ordered the radio for my nephew, said it would have to be changed, he knew beforehand that I would need this done being that it was going to be used with Futaba equipment!

The only Tx crystals I have are the Multiplex brand and I don't own any FM only radios at all. Most of my gear is Futaba but I do have a JR XR2 AM radio.

I emailed Multiplex USA several times and exchanged information with Karlton Spindle who stated that I could use ANY receiver (positive or negative shift) as long as I used the brand of Rx crystal designed for the receiver. In my case, I have a brand new Hitec receiver using brand new Hitec Rx crystals. Damn!

I have another email into Karlton as of last night so I hope to hear from him soon.

I will not be sending my transmitter in to have any work done, but will instead sell the Hitec FM receiver and crystals and get something from JR or Airtronics instead.

You don't happen to have any crystals for your AM JR receiver that match your Multiplex ones by chance do you? If you do you could try using the radio with that receiver to see if it will work, I would think that it should! Hope everything works out for you, let me know if you get it working or not.

OK guys......here is the latest scoop.

Seems the Profi 403 transmitter will transmit in both AM and FM all using the same module as long as you use the Multiplex transmitter crystals.

When in AM mode, you can use ANY brand receiver. That means Hitec, Futaba, JR, Airtronics, KO, Novak, Tekin and others. The only catch is you must use the same brand of receiver crystal, meaning a Futaba receiver must have a Futaba crystal and so on. I tested this out with my Futaba gear and all is well. Neat!

When in FM mode, you cannot use Hitec or Futaba receivers or any others that are designed to be used with these brands. Apparently, according to the tech guy at Multiplex USA only receivers from JR, KO, Airtronics and Multiplex will work.

So in a nut shell, the brand new Hitec 3-channel FM receiver and the four brand new Hitec FM receiver crystals I just bought are of little use to me. I sure wish Multiplex USA had told me this before I spent all my money. I even asked and they told me I could use any brand receiver.

Anybody want to buy a receiver and some crystals?

SteveM: Being that they didn't give you all the info to start with, you should call and see if you can get their techs to change the shift for free instead of buying different receivers! It's a long shot, lol, but hey you never know! The Am info you gave is new to me though, thanks for the info, I thought you would need the shift changed for Futaba or Hitec if you were on AM also. Well my nephew has FM Futaba equipment, he had the shift changed over and it does work flawlessly, I guess the only drawback is the price of having it done and now he has to stick to Futaba and Hitec components! If he wants to use another brand it would have to be switched back!

Well, if I go to the trouble of having my transmitter switched from one shift to another I could then use the Hitec gear I just bought. The fact that I am in Canada and the service depot is in the States complicates matters so I might just as well leave it the way it is and sell off the Hitec receiver and crystals.

I too am surprised that this Tx will work with any receiver in AM mode. I don't know how they managed it, but it seems to work just fine. Too bad that same trick doesn't work in FM mode.

For Sale
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- NIB Hitec FM 3-channel receiver @ US$45
- NIB Hitec FM crystals on channels 67, 70, 80 & 81 @ US$10 each