Does the antenna get in your way? - TIP

[Jack]

Hello, I am new to FMS and this Forum so perhaps someone else has mentioned this, if not, I found this trick to be very helpful. After constructing the parallel interface, the extended transmitter antenna kept getting in my way. Since it must be extended when the radio is turned on, I cut a piece of soft wire the same length as the full extension of the transmitter antenna, soldered an alligator clip to one end, pushed the antenna back down and clipped the alligator to the top of the antenna. Problem solved! If you have a few inches of antenna sticking out when it’s in the fully retracted position, be sure and subtract that from the length of your wire. The idea is to get about the same length of wire as a fully extended antenna to properly load the final power transistor.

[Steve Lewin]

It's an interesting approach but I find it easier to simply remove the crystal which stops the Tx from transmitting. No need for an antenna then.

Steve

[Jack]

Good idea - as an alternative, you can pull the crystal from the transmitter and leave the antenna retracted. The transmitter still has to be turned on so it's six of one and a dozen of the other - it is easier for me to clip the wire on. By the way, the TX is not putting out any RF with the crystal out so as an added bonus,if you are getting objectionable noise, that would stop it.

[Isaac]

I have a better solution for the antenna/crystal problem:

I built Vitaly Puzrin's PIC interface, but made some changes to the circuit and to the PIC software(I have already sent the diagrams to Vitaly, but I think he has not published them yet). I added a power input (J4 jack) with two diodes (1N4007) and a voltage regulator (LM7810) to the circuit, and connected the output of this circuit to pin 1 of the 6 pin DIN plug (my radio is a Futaba Conquest FP-T4NBF).

So I use a wall outlet transformer (12V 300mA) plugged to the cable's J4 jack to power the TX from the cable.
No need to power the TX on, or removing crystal or even extending the antenna. And no need for a charged battery (you can even charge your battery while playing the sim, just plug the charger as usual).

I tested this circuit with my TX (Futaba Conquest 4ch) and with my brother's TX (Futaba Skysport 4ch).

If someone is interested in this circuit I can send the diagram via e-mail.
My e-mail is imb@cefetgo.br or isaacbavaresco@yahoo.com.br

NOTE: I assume no responsability about damages. This circuit is the one I use every day, and for me it works great.
I don't know if this schema works with radios other than the ones I tested (altough it is likely to work).
If you are going to try this circuit, It's better you know enough electronics not to burn your TX.