Futaba radio help

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spider
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Futaba radio help

Post by spider » Mon Mar 12, 2018 2:09 am

Hey guys,I have an old Futaba Magnum Jr FP-t2pka radio transmitter. I last used it about a year or so ago and stored it in a climate controlled area.
This year I went to use it and placed good working batteries in it and found it doesnt work. I checked the batteries with a Digital Multimeter and all batteries are good. I flicked the power switch again and the voltage meter needle doesn't move. I tried the batteries in another transmitter and it worked. I went back to the non working transmitter and took the case apart. Plug the batteries into the slot and checked to see if I had power where the red and black wires are connected to the contacts. I do have power there. But this is where I need someone with electronics knowledge to lend a hand to guide me on how to check other things with the DMM to find out what went wrong with it.

Anyone that can help with this? I dont want to discard the piece as its for a vintage r/c car that I want to keep running a nicd pack through. I would like to use it as a project on how to fix something electronic. I looked for the schematic but cant seem to find it online. I suppose due to the age of it.

I found the manual here. https://www.manualslib.com/manual/37824 ... -2pka.html
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Vintage-Futaba-Magnum-JUNIOR-FP-2PBKA-Bin-64 (1).jpg
Last edited by spider on Mon Mar 12, 2018 2:13 am, edited 1 time in total.

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GoMachV
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Re: Futaba radio help

Post by GoMachV » Mon Mar 12, 2018 2:12 am

I can’t say on that one, but I think I have a brand new one stashed away that I removed the back from and gave to another member. Everything else was brand new and unused. Your welcome to it for the cost of shipping if you want it. I will just need to round it up, hoping I didn’t toss it
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RC10th
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Re: Futaba radio help

Post by RC10th » Mon Mar 12, 2018 2:16 am

Dicky switch maybe?
I was old school - when old school wasn't cool !

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tamiyadan
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Re: Futaba radio help

Post by tamiyadan » Mon Mar 12, 2018 3:15 am

the switches on futabas get corroded.
also the battery holders get corroded and flaky.

when you put the batteries in the holder for the radio test the output leads and see if you are getting full voltage.
if not then you need to use some plastic safe electrical cleaner on the battery holder and then lightly sand the contacts and springs and try the batteries again.
sometimes the holders are bad enough they need to be replaced with a new holder from old stock on ebay or an electrical supply house.

next pop the cover off the power switch and flick it a few times back and forth and press on it a little and see if the meter moves.
usually you have to take it apart and blast out the power switch with electrical cleaner.

from there it gets more involved figuring out what is stopping power from flowing.

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spider
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Re: Futaba radio help

Post by spider » Mon Mar 12, 2018 3:42 am

GoMachV - Please let me know if you find it. I would be interested. :) Thanks
RC10th - is that the main switch?
tamiyadan - the battery holder is okay. I usually spot that first and if corroded I normally clean em up. So we can eliminate that one. :) As for the switch, I wasnt aware of that. Ill have to check that out more. I assume I should be getting 12 VDC on the battery holder correct?
I think I have some radio shack tuner control cleaner. Would that be useful and do the job? Or would doing a baking soda or vinegar soak work? The only place I can think it may have some corrosion is in the cavity of the positive terminal. Ill have to recheck the batteries as well. I know one or two tested 1.2 volts so maybe its not reaching a working voltage level too? I never dropped it and havent really used it much. *scratches head*
Thanks for all the fast response guys. Much appreciated.

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spider
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Re: Futaba radio help

Post by spider » Tue Mar 13, 2018 6:06 am

Well thanks guys for all the help. I ended up re-testing each battery and found two of them completely dead. Why they tested good the last time is beyond me. Each battery was around 1.3v to 1.5. Today I retested for giggles and found two with .200 to .394. Popped a couple new ones in and tested the transmitter and the meter peaked. Yay!!! Thanks again fellas. Much appreciated.

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Phin
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Re: Futaba radio help

Post by Phin » Tue Apr 10, 2018 2:48 am

I have one of these (it was my first radio) but I've been under the impression that they weren't legal to use in the US anymore because they're wide band?

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jwscab
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Re: Futaba radio help

Post by jwscab » Tue Apr 10, 2018 11:59 am

Not sure the radio police are paying much attention to these bands anymore, but maybe......

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