Another Interesting Question! - Maybe?

[Eagle Al]

I noticed that Tom's RC sells self-powered interface cables. That is they don't depend upon the TX's batteries. In fact, he cautions making sure the TX switch is off and advises removing the batteries.

Is this a better idea than depending upon the TX to supply power? I've also read that using a TX without a load (the flight pack) can burn it out?

Regards,

Al

[sssfox]

I have one of his interface cables and the power cable works fine. My understanding is that, on Futaba, the output is turned off when power is supplied through the buddy box connector and two of the pins are shorted, which they are on his cable. If you search the posts, you will see that there is a problem with Tom's interfaces and some of the new Dell computers.

The load on the transmitter is supplied by the antenna. The transmitter has no idea whether the flight pack is turned on or not.

You can burn out the output section if you run the transmitter for any length of time with the antenna retracted or removed. As a precaution, I removed the RF module from the back of the transmitter that I use. It also prevents the possibility of interference with someone else who may be flying. It is a very remote possibility in my area, but you can't be too safe.

[Eagle Al]

sssfox:

Thanks for your response. I am finding selecting a cable to be a big task, so any help is appreciated. I've already bought and returned one serial PIC cable (it didn't work), so I am being more diligent this time in the selection process.

I am slightly confused about your post though. If you bought one of Tom's powered cables, why did you have to remove the RF section from your transmitter? With the batteries removed, the TX wouldn't work.

BTW what kind of cable did you buy (serial Pic, USB, or parallel)? I have a VG400, and his Buddy Box editiion looks interesting.

Regards,

Al

[sssfox]

I bought the USB cable.

The transmitter does work with the powered cable plugged in, if you turn it on. There is the possibility that someone could turn it on and burn out the rf section.

As I said in the earlier response, I think the rf section is disabled when two of the pins in the cable are shorted, but I don't have any way of checking. On the transmitter I own, it is easy to remove the rf module, it just plugs in.