abacro

How many of you pilots out there using JR Radio's know that they are the ONLY radio in the hobby that has 2,count them 2, small glass,1.5 amp fuses between the tx battery pack and circut board? And do you know what happens when only 1 of the 2 fuses blow while you planes in the air?


Good luck landing!

olivier

Hi,

You lose your plane, but your transmitter is still working after renewing the fuse. Without the fuse, the smoke from your transmitter could reduce visibility to see where your plane is going to crash...

No, seriously, I suppose that some technical engineers had good reasons to fit some fuses (for the other type of charging-cable (negative in centre, positive on the shield vs. other brands?).
Olivier

stuk_at_work

My Feedback: (111)

If you really draw more than 1.5 amps through your transmitter battery, odds are you are about to crash anyway, whether or not the ckt. is fuse protected or not. You can "ask Danny" what the nominal current flow is from the battery, but I bet even 1/2 amp is a high estimate. Draw much more current than "normal" for even a short period of time and you probably will cook some ckt. board anyway that would also result in a loss of control.

Are you afraid these fuses will blow while you are in the air? I've replace about a dozen fuses on (4) different JR transmitters over the last (3) years. Every one has failed when plugging a charger into the transmitter, both "wall wart" and "smart" chargers. None have ever failed when the transmitter was on, or even switched on.

Silent-AV8R

My contacts at JR told me that 250 mA is about average for the TX.

Here's a trick. Turn your transmitter on, then plug in the charger, then turn the TX off. You will never blow a fuse this way. When the TX is on the charge circuit is dead. You cannot cause a short when inserting the charge jack when the circuit is dead. Works like a charm.

stuk_at_work

My Feedback: (111)

And to think of all the time I've wasted swinging a dead chicken around in the air!

Seriously, it sounds logical, and I will start using this procedure and see if it makes a difference.

garch 22

My Feedback: (7)

Abacro, I have three JR transmitters, and all have a single 3 amp fuse between the battery and circuit board. Curious that you have 2 - 1.5 amp fuses in yours. Which model transmitter is it?

Mac_Man_UK

I cant think of a single JR transmitter that has 2 fuses.

[8D]

GJr.

My Feedback: (3)

Usually, it is a short form a worn, broken, or cracked insulating ring around the charge pin connector that causes problems for the fuse.

captinjohn

I only see 1 (one) fuse in my JR X347. It has never blown yet. I should get a extra....what size is it? Thanks Capt,n

proline8000

My Feedback: (12)

I have had many radios from Kraft,Proline,Ace,Futaba,Airtronics,and JR. I only fly JR now and it was a hard thing to give up my ACE Micropro8000 but it was time. We added a 1 amp fuse on the ace radios to protect the input inductors during use and batteries during charging on the power circuit. Airtronics has a diode on the charge circuit to protect the battery if the wrong polarity is applied during charging. I don't know what Futaba uses but I will never use one again.