Fun, Learning, Friendship and Mutual Respect START  HERE

Go Back   HeliFreak > R/C Electronics Support > Spektrum FBL System > Spektrum FC6250HX

Like Tree1Likes
  • 1 Post By brianbremer
LinkBack Thread Tools Display Modes
Old 08-21-2020, 05:12 PM   #1 (permalink)
Registered Users

Join Date: Aug 2020
Location: ottawa, canada
Default FC6250HX + 2nd 4651T? 4pins or 3 pins?

I just got the time to try setting up the FC6250HX, it's included 4651T satellite and for good measure I bought a second 4651T since it is going into a Trex 500.

There is no place to plug a second SRXL telemetry satellite on since it has a 4 pin connector and the rx1/rx2 ports are 3 pins only.

Reading the marketing stuff online, including the online manual it is implied that simply using 2 of the same satellite type is required for larger helis. They even use the phrasing that it supports 2 SRXL Telemetry satellite receivers.

According to the manual, pin 2 is N/C which means the sat really should have a 3 pin connector. The sat supplied in the kit uses an adapter to plug into a 3 pin servo port (leftmost) which seems not to be a problem.

I have a couple of older DSMX satellites that use the 3 wire interface, and was wondering if anyone (Brian?) knows if splicing a 3 wire onto the 3 used wires of the 4 wire loom would work?

I tried using the 3 wire sat from an AR8010T but it would not bind with the flight controller.

I struggle to understand why a 4 wire sat is supplied with an adapter to NOT use in a the rx1 and rx2 dedicated ports? In a brand new offering?

I would just take it back, except my 'local' shop is an hour's drive away. If this would work I would like to save the time and gas and use what I got.

Has anybody tried adapting their mis-purchased 4651T to the rx1 port? I'm not sure what kind of trouble I might be courting,,,
murdog44 is offline        Reply With Quote Quick reply to this message
Sponsored Links
Old 08-23-2020, 10:55 AM   #2 (permalink)
Registered Users
Thread Starter Thread Starter

Join Date: Aug 2020
Location: ottawa, canada
Default Found the answer elsewhere on the forum!!

Apologies for not searching better! I am new on this forum, and not well acquainted with the breadth and depth of knowledge on these forums.
There was a thread from January to March on this very subject. Apparently there is an adapter being made to perform the 4-3 pin conversion : DXS DX3 USB Serial Adapter SPMA3068 . As well, it has been confirmed that wiring one end into a jst-3p connector in the DSMX receiver configuration (detailed in
I had an old ar6200 dsm2 with 3 wire sat, and scavenged one end connector to set 3 of the female pins in place of one of the connectors from the 4 wire connector. Bound both using the bind button on each, and now have solid orange light on both remotes and a green light on the 6250.
The post was on the main forum, starting on page 5. Keyrigger graciously posted photos of the same wire mod!

I am very glad to have found this site, and again apologize for repeating a question that has already been answered!
murdog44 is offline        Reply With Quote Quick reply to this message
Old 08-23-2020, 07:26 PM   #3 (permalink)
HF Scale Support
Posts: 4,079

Join Date: Jan 2010


You cannot connect more than one 4651T SRXL2 remote receivers to the 6250 at the same time. Port RX1 on the side is for standard DSMX remotes like the 9645 or 9746 as examples. The side RX2 port is shared with the BND/PRG/RX2 on the main bus but only one remote can be plugged into that shared port. I had bought one thinking the same but there are more uses for my extra 4651T in the future as I will be getting another gyro for one of my scale builds. There is no advantage gained by a second SRXL2 remote which was pointed out to me by Brian and a third remote is generally not needed in the normal application that this gyro is used in. I have mine in an 800 Diabolo and seldom have more than a few fades on the DSMX remote and mostly no fades on the 4651T. The F3C maneuvers are generally flown at or near the limit of vision for the entries and exits. Hope this helps.

Keyrigger is offline        Reply With Quote Quick reply to this message
Old 08-23-2020, 07:33 PM   #4 (permalink)
HF Scale Support
Posts: 4,079

Join Date: Jan 2010

PS: If you would like a suggested mounting point for the 4651T, I would mount it on the boom with the two whiskers mounted either side of the boom at an angle outwards. You do not require a second remote attached to be able to use the gyro and the second one is there for redundancy and would be mounted with its antennae in a different plane to the main remote. If you are really stuck, you can PM me and I can give you a call. Unlimited long distance, love it. Take care.

Keyrigger is offline        Reply With Quote Quick reply to this message
Old 08-24-2020, 04:20 PM   #5 (permalink)
Registered Users

Join Date: Sep 2010

You can use two srxl2 telemetry remotes, one in the front data/bind/rx2 port and one in the side rx1 port. Only one of them will be used to transmit telemetry back to the transmitter so there is no real advantage to using two of them.

You can also use a non telemetry dsmx remote with the rx1 port.

I recommend sticking to remotes that utilize a external antenna so the antenna can be placed away from the c/f frame, based on that I recommend against using the spm9747 srxl2 remote.

The remote type will be auto detected, the telemetry log screen on your transmitter will show L: 6250 (indicating 6250hx flight log) and R: is the number of remotes connected.
Bluebell likes this.
Horizon Hobby, LLC
My Projects: 150 S, 200 SRX, 200 S, 230 S v1/v2, 270 CFX, Fu270, Fu480: AR636/AR6335 Heli, FC6250HX, AR6250MHX
brianbremer is offline        Reply With Quote Quick reply to this message

Quick Reply

Register Now

In order to be able to post messages on the HeliFreak forums, you must first register.
Please enter your desired user name, your REAL and WORKING email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself. Use a real email address or you will not be granted access to the site. Thank you.
Email Address:
Where do you live? ie: Country, State, City or General Geographic Location please.
Name and Lastname
Enter name and last name here. (This information is not shown to the general public. Optional)
Helicopter #1
Enter Helicopter #1 type and equipment.
Helicopter #2
Enter Helicopter #2 type and equipment.
Helicopter #3
Enter Helicopter #3 type and equipment.
Helicopter #4
Enter Helicopter #4 type and equipment.


Thread Tools
Display Modes

Posting Rules
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

Copyright © Website Acquisitions Inc. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2022 DragonByte Technologies Ltd.

SEO by vBSEO 3.6.1