Go Back  RCU Forums > Radios, Batteries, Clubhouse and more > RC Radios, Transmitters, Receivers, Servos, gyros
Reload this Page >


RC Radios, Transmitters, Receivers, Servos, gyros Discussion all about rc radios, transmitters, receivers, servos, etc.


Old 01-07-2024, 02:57 PM
Thread Starter
Join Date: Feb 2005
Location: Centreville, VA
Posts: 54
Received 1 Like on 1 Post
Default OLD Futaba PCM and PPM FP-T8SGH, FP-T8SGA-P and FP-T8SSA-P

Hi Guys,

First off I am just trying to get some history related to the transmitters I have in my possession. Specifically the FP-T8SGH one.

Also - I have been doing this stuff for a long time and I know the difference between PCM (512) and PPM transmitters. I have built my own transmitters using various cards and open source software. So I am trying to stay out of that Rabbit hole. :-)

What I have in my possession are three different Futaba transmitters. A single stick and two dual stick radios. Two of the radios are PCM and the other is a very rare version of the same dual stick but outputting PPM. If you look at one of the pictures you will see an FrSky DFT module in the back. This module uses the PPM signal from the transmitter.

The PCM versions use a T730 card and the PPM version uses a T687 card. These cards have the microprocessor that either outputs PPM or PCM to the transmitter's module. They also regulate power from the battery to some extent to the rest of the components.

My history question is this. Does anyone know if other models of Futaba transmitters that used the T687 card? Does anyone know the history and the reason Futaba created different versions of the same transmitter?

I have flown a plane using the Futaba FP-T8SGH with a FrSky D8R-II receiver and it worked great.

Just a thought. Both of the PCM transmitters module ends with a "P". I wonder if the "P" means it is the PCM version. As you can see the FP-T8SGH does not end with a "P" so I assume that means it is not.

The three Futaba transmitters. Two PCM and one PPM using the T678 card to create the PPM signal.

Showing he back side of the three transmitters and aT687 card on the table. The PCM transmitters use a T730 card.

Closeup picture of the FP-T8SGA-P showing the PCM emblem.

Close up of the FP-T8SGH (Heli version). Notice there is no PCM emblem on the lower left side.

Close up of the back of the FP-T8SGH (Heli version). You can clearly see the FrSky DFT module.

Photo of the Futaba T730 PCM card. This card is a multifunction card but had a small processor that converts the PWM signals into a 512 PCM signal.

Close up of the T687 card. This card outputs PPM.
transmitter module. It works and works great because the transmitter outputs a PPM signal.

If you look closely at the photos you will see that two of the transmitters have the Red PCM label on them while the other has no label and has a silver face while the other two have a gray face.

Last edited by esmithga; 01-08-2024 at 12:27 AM.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.