I just tried to post this in the JR & Spektrum area but was denied. Seems that forum is closed.

Yesterday, I was out at our main field and was going to fly my Skylark 70. The weather was absolutely gorgeous.. temp about 78 degrees, wind about 5 knots and right down the runway centerline. It was partly cloudy, in other words, perfect RC flying weather.

So, I put the connectors on the wing servos, mounted and bolted down the wing, then fueled it up. Ah.. here we go..

So, I got the 2.4GHz frequency pin (yeah, we use it for 2.4 GHz only to make sure we have a count on how many people are ready to fly at any given time) and went back to the assembly table.

I turned the TX on then the RX. Nothing.. no response from the RX. I checked the voltwatch, and it was all the way over in the green, so I knew the RX battery was ok, but nothing.

I looked at the TX and the screen was blank. I immediately suspected the battery, so I removed it and put it on the field charger at 3 amps charge current (don't sweat it, it's a 1500 mah battery) but it peak detected only after about 10 minutes. The battery was fully charged. So, I put it back in the TX and tried to turn it on. Nothing. What gives here?

So, I de-fueled and, as I was steaming, I packed up and headed home. When I got home, I called the Spektrum support line and talked to one of the tech's. He suggested that I check the fuse. Fuse? Ok.. so I did. It was open!! What happened to cause the fuse to blow?

Well, suggestions came back from the Horizon folks. Back up two weeks.. I had been flying two Wednesdays ago, in fact, I got in four or five flights. When I was done, I packed everything up and left for home.

When I got home, I had to take care of a few things so I did and that took me about 2 hours. Then I went to the car and noticed that the transmitter had been left on. Oh man... so I shut it down. It had been on for about two and a half hours. The next time I tried to turn it on was yesterday, at the field.

Horizon suggested that a probably cause of the fuse opening was that the battery was allowed to get to low, and the fuse opened when either shut the thing off or when I turned it on yesterday. I can understand both issues, this happens. I won't bother to explain my reasoning, but it happens some times.

I did not have a spare, so I have to stop by an automotive store or Radio Shack and pick one up tonite. One of three things will happen.

1. The TX will come up normally and be ok.
2. The TX will come up but open the fuse again. Meaning, a problem with the radio and back to Horizon it goes.
3. The TX will come up, but it will burn something up then open the fuse again. Meaning, again, a problem and back to Horizon it goes.

So, if you happen to have the fuse open on you, by the way, the fuse is located behind the RF deck inside the TX. You remove the six screws that hold the back on, then the four screws that hold the RF deck on, and the fuse is right there, a 1/4 inch x 1 inch 3 amp tubular fuse.

CGr.

Atleast you learned how NOT to cycle your battery!

Yeah. Checking it with a voltmeter was not an option because I left that at home.. [:@] So, my only option was to hang it on the peak charger and see what happened. It didn't take long to find out that it was fully charged already. And that WAS the bad news because that meant that the TX was giving me a problem. No-fly day yesterday after all. []

Nothing worse than getting all excited about finally getting to go flying and forget something, or something happens to keep you from flying [:@] !

Yep. I was really excited because the weather was perfect. I was psyched.. ready to burn some fuel. I even took two extra gallons of fuel with me!! (ha.. burn two gallons of fuel.. would be quite an afternoon!!!). But, it was just not to be.

CGr.

Keep an eye on that Dick. I had a JR Tx that blew a fuse about once a month till it went back for a new one.

It doesn't sound reasonable to me that the fuse should blow under the described conditions. Sounds more like PFM.

Those of us with Futaba charge leads that take our first forray into spectrum often replace a fuse or two as the center pin is hot on Futaba and in JR the center pin is ground.

Also charging at too high of a rate will blow it.

Leaving it on too long won't.

I tried to recharge my Spektrum at too high a rate once and blew the fuse in my radio. Scared me at first but the fuse was easy to change.

Does anyone know how to program a DX7? Iam trying to program FLAPS .....on my F-22 Raptor!!!!!

Do you have the name, etc. of these fuses? It might be nice to have a few on hand.

Well, I went to the automotive store last evening (as suggested by the Spektrum service tech) to get a replacement fuse. They did not have the correct size (physical size that is).

Next stop will be Radio Shack. In the mean time, I am going to try to order the replacement from Horizon.

Yeah, Mike.. I will keep an eye on that. This is somewhat unusual. And, of course, if it opens the replacment fuse, then I will KNOW there is a probem and get that radio on over to Spektrum for repairs.

It was just odd. The wall wart charger is the only one I use on that radio because the peak detector will not work because of the reverse protection diode in the radio. And, I won't remove it or short it out. So, I either remove the battery and can peak-detect charge it that way, or use the wall wart charger with the battery installed. Either way, the fuse should not be an issue. If using the Peak Detector method, the battery is removed from the radio.. thus no fuse. If I use the wall wart, well, it's designed for this AND the fuse should not open.

I'm stuck with the belief that either it was a freak occurrence OR there is a valid problem. As soon as I get a correct replacement fuse, I will find out.

CGr.

Radio Shack stocks the proper fuse, if memory serves its a 250v 3amp fast blow.

Thanks for the info. The Radio Shack I stopped by last eve did not have it, and the guy behind the counter had no idea what I was talking about.

I have a few more RS's in the area. will visit another tonite.. may get what I need. I knew it was a 3 amp, however, it is a tad smaller (physically) than the automotive fuses, at least the ones I looked at last eve.

Thanks, Andy, for the update.

CGr.

BarracudaHockey
How did your season go. Red Wings still in it.

We made it to the finals and lost to the number 1 seed. The Flyers remained alive last night.

You talked to some dweeb, at my RS they have a stack of metal drawers full of electronics parts, one of them is an assortment of fast and slow blow fuses, the right one is in there if its in stock.

Some dweeb is right!! I am now informed and I will get my fuse!!!

Oooh.. Flyers.. (live about 60 miles from Philadelphia.. went to a fight, a hocky game resulted.. oops, bad joke) Were watching the Flyers. Maybe a winning team this year?? Maybe??? Eagles, Phililes, 76'ers.. can't do it. Maybe the Flyers this year.

Thanks, Andy.

I got my fuses at Radio Shack. The number on the package is 270-1054, and come 4 to a package.

Thank you for the information.

Does anyone really know how to program a DX7 for flaps?

Paulmv,
Start your own thread and someone will be glad to answer the question. I could answer it, but I won't because it's considered somewhat rude to hijack someone elses' thread with a completely different question....

My BAD! Please forgive my not knowing...And Thank You! When you know better,you do better....

I left my JR transmitter plugged into the sim over night and blew the fuse. that was a year ago and it has been fine since. Yours should be fine also.

David

Thanks.

I went to RS yesterday, they had the fuse. So, I replaced it and the TX came up normally. I will watch it closely for a while to make sure it doesn't open on me again.

CGr