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I'm missing an era correct Tx/Rx for a recent RC10gt build.

But I have a Futaba 3PJ Super from the late 90's, the manual says it has an (8) model memory.
The FM/PCM has a failsafe/throttle cut, so I bought this with a Kyosho USA-1 Nitro Crusher, back then.


Didn't notice that mine is the 27 MHz FM/PCM band:


- and when I went and tried to order the same Rx model number FP-R113iP I already have, which is 27 Mhz:


I accidentally bought the 75 MHz instead.



Regarding 27 MHz:
When I went looking for the 27 MHz FM Rx Channel 4, crystal, that I would need to match my Tx, there were very few 27 MHz crystal choices, at all, whereas the 75 MHz FM crystal selection seemed to be much larger. Is that possible, that there is a wider selection of 75 MHz crystals, than 27 MHz?

Ultimately, I would like to have more than (1) car on the Futaba 3PJS, but would I be better off finding a Tx module for the 75 MHz band, in order to find a matching set of (3) crystals?

Hope any of that made sense. Thanks!

There are many more 75MHz frequencies available than 27MHz, which I think there are only six frequencies in the USA. Regarding your TX module switching from 27 to 75MHz, I'm not sure that's possible. But I'd like to know too because I have a PCM1024 FM Futaba that has the module. But I was always under the impression that while you can switch freely through the different frequencies available within your module (FM/AM 27/72/75), you could not switch outside of that module. And switching the module to something different, I'm not sure about. Hope someone can answer that definitely knows for sure.

As far as I know the modulation is in the module so I think you can freely swap module bands. I know the earlier radios had different length antennas based on the band 27/75mhz.

I believe the 27FM/PCM was designed for international travel as most countries allow the 27mhz band.

Ideally you'd want to find a Spektrum SM1001 module so you run spektrum receivers

OldSchoolGuy wrote: ↑Thu Dec 07, 2023 12:38 am There are many more 75MHz frequencies available than 27MHz, which I think there are only six frequencies in the USA. Regarding your TX module switching from 27 to 75MHz, I'm not sure that's possible. But I'd like to know too because I have a PCM1024 FM Futaba that has the module. But I was always under the impression that while you can switch freely through the different frequencies available within your module (FM/AM 27/72/75), you could not switch outside of that module. And switching the module to something different, I'm not sure about. Hope someone can answer that definitely knows for sure.

The modules that allow you to change your Tx band, specifically on the Futaba 3PJS, are called Futaba FP-TJ-FM.




So far I've seen the modules for AM 27 MHz, FM 27MHz, FM 75 MHz, and Dual-Conversion 72 MHz. Was thinking about buying this one: https://www.ebay.com/itm/175958184701 - for the FP-TJ-FM 75 Mhz, and selling my leftover 27 MHz module and Rx.

RC10th wrote: ↑Thu Dec 07, 2023 1:36 am As far as I know the modulation is in the module so I think you can freely swap module bands. I know the earlier radios had different length antennas based on the band 27/75mhz.

I believe the 27FM/PCM was designed for international travel as most countries allow the 27mhz band.

Ideally you'd want to find a Spektrum SM1001 module so you run spektrum receivers

That's really interesting that 27 MHz is more for international use.

That's also excellent that Spektrum makes a DSM module for the Futaba, that would make this Tx useful still. I could only find one of those in Germany, I emailed the seller to see if he would ship to the US.

Here are the sellers pics:




But if I'm going to use Spektrum, and not an era correct Rx, I do have this already:


If that seller won't ship the Spektrum module/Rx to the US, I might just go with the newer Spektrum Tx/Rx:


Thanks guys!

The eBay seller in Germany never got back to me about the Spektrum SPM1012 kit, with the SM1001 and SR3001.

But I found the earlier version though, which is closer to era correct for the USA-1 NC, and GT.
Seller's pics, these are on the way - still has the plate wrappers:






No more crystals! Will buy a few more SR1000 Rx for the other cars now. So stoked. Thanks again for the heads up on the Spektrum DSM module, @RC10th !