Futaba FP-2PB (Magnum Sport) TX batt. holder

roddie Sun Jul 07, 2024 6:53 pm

I tried to power mine up today.. but had issues. Firstly.. the TX batt. holder (a separate modular piece which holds X8 AA cells) was very snug-fitting into the handle of the pistol type radio. Once installed.. wouldn't power-on. I thought I'd put it in the wrong way.. but not.

Check it out.... Mad

Futaba FP-2PB (Magnum Sport) TX batt. holder Futaba10

Any ideas on how to fix that?

roddie Mon Jul 08, 2024 7:50 pm

A little history. This radio was purchased from Tower Hobbies in the early-mid 1990's for use with my Dumas "Short Stuff" (DV10) boat.. and had been used "on and off" over the years in other model boats. Until yesterday; the radio set had been in storage for at least a decade, in a box with my other radios.

The negative (-) side of the batt. holder had corroded.. and its' connector compromised. There were no cells in the holder while in storage.

The out-of-production/no-longer-available Futaba replacement part number is S10730

I had a small sheet-metal screw that was the perfect size to self-thread into the rivet-hole remaining in the connector. I used a very short metal stand-off (alloy tube) and flat-washer to match the height/circumference of the existing (complete) positive (+) side connector. It "looked good"...

Futaba FP-2PB (Magnum Sport) TX batt. holder Fp-2pb10

Futaba FP-2PB (Magnum Sport) TX batt. holder Fp-2pb11

The batt. contacts inside the transmitter's handle are two "springs" (see photo below)

Futaba FP-2PB (Magnum Sport) TX batt. holder Fp-2pb12

No power... after inserting my repaired part... DAMMIT!

So........... I check voltage at the repair-site. 12VDC.................

I guess I should connect to those spring-contacts inside the handle-tunnel via an alternate method.. and apply the 12VDC to see if the TX powers-up... Neutral

MauricioB Tue Jul 09, 2024 12:18 am

Hello friend, this is the work I did for my two Cox-Sanwa 2 and 3 channel radios.
Those battery receptacles, in one way or another, break or make false contacts, which can cause you to lose control of your model, so I'm going to play it safe. Here a detail:
1) I open the radio equipment.
2) I connect two cables, one red and one black, positive and negative to the internal battery contact plate.
3) I place a connection card.
4) I put together a battery pack in the appropriate way for the place where it should be housed.
5) The batteries in the pack are soldered with tin and with brass sheets between them. Then I put heat shrinkable material.
6) I connect the battery.
7) The problem is over.

Sorry Roddie, some photos don't have the best quality!

That cable with the plug goes inside the radio control and you must house it so that it does not interfere if at some point you place the socket with batteries again. As you see, you have two options to power your equipment at the same time. One way does not cancel the other, you only have to use one way.

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240720

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240721

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240722

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240723

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240724

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240725

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240726

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240727

roddie Tue Jul 09, 2024 10:00 am

MauricioB wrote:

Sorry Roddie, some photos don't have the best quality!

That cable with the plug goes inside the radio control and you must house it so that it does not interfere if at some point you place the socket with batteries again. As you see, you have two options to power your equipment at the same time. One way does not cancel the other, you only have to use one way.

No worries Mauricio Smile

Thank you for showing me your repair example.

The box that my radios were in, had gotten exposed to dampness at some point.. and I'm afraid that there could be other internal connections/components that may have been compromised. If I can't get the TX to power-up; I will open the case and inspect the inside. I may do that anyway.. because those spring connectors inside the handle/grip are not easy to access.. other than using the battery-holder that was designed for it.

Thank you again my friend Smile

roddie Wed Jul 10, 2024 4:04 pm

I took the TX apart yesterday.. which made it possible to easily connect to the spring-terminals inside the handle using a 12V charger with alligator-clips.

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240731

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240732

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240733

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240734

Good.... and it operates the servo and speed control in the boat. Now it was just a matter of providing a reliable power connection when it's reassembled... Neutral

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240735

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240736

Futaba FP-2PB (Magnum Sport) TX batt. holder 20240737

Day-two of my water-trials in the swimming pool. Lots of problems.. but mainly intermittent TX power. DAMMIT!

The battery-holder design makes it difficult to fix. It fits too tightly inside the handle.. and must be "pried-out" with a flat-blade to remove it. Rolling Eyes

I'm afraid that the brittle plastic of the handle is going to break. I need to wrap a ribbon around the bottom.. and up both sides of the holder before putting it back in.

more on this later..

davidll1984 Fri Jul 12, 2024 6:06 am

I have this same magnum controler This was my first controller It still works a good thing with the receiver it can take up to 8 volts i was using a 7.4 v battry pack in m'y boat It served as weight and I never ran out of battery but it was a big boat you could use a small 7.4 lipo wit the Reciver without trouble

roddie Fri Jul 12, 2024 6:44 pm

davidll1984 wrote:I have this same magnum controler This was my first controller It still works a good thing with the receiver it can take up to 8 volts i was using a 7.4 v battry pack in m'y boat It served as weight and I never ran out of battery but it was a big boat you could use a small 7.4 lipo wit the Reciver without trouble

Yes.. It was when BEC circuitry was in its infancy. I ran 7.2V and alternately 8.4V NiCd packs in the "Short Stuff" boat back then.

My radio set came with Futaba's MC210CB ESC option. It still seems to work. The "glitchiness" of the throttle; I'm guessing is RF related.

Futaba FP-2PB (Magnum Sport) TX batt. holder Img_2011

Futaba FP-2PB (Magnum Sport) TX batt. holder Img_2012

Sponsored content

Futaba FP-2PB (Magnum Sport) TX batt. holder

Futaba FP-2PB (Magnum Sport) TX batt. holder

Re: Futaba FP-2PB (Magnum Sport) TX batt. holder

Re: Futaba FP-2PB (Magnum Sport) TX batt. holder

Re: Futaba FP-2PB (Magnum Sport) TX batt. holder

Re: Futaba FP-2PB (Magnum Sport) TX batt. holder

Re: Futaba FP-2PB (Magnum Sport) TX batt. holder

MC210CB ESC

Re: Futaba FP-2PB (Magnum Sport) TX batt. holder