RT524 & MX-6707 Antenna setting? - Steel Soldiers::Military Vehicles Supersite

decodeme2 · 01-13-2010, 12:23

Hi,
Looked all over here and cant find the Antenna setting for my rt524 radio in my hmmwv.
I hooked it up, powers up great. Antenna makes a clicking sound when i change channels. A FAN comes on when i transmit. I have a buddie who is 25 miles away id like to call to see if it works, i also will try and get a tv channel in useing the channels i found on this site..
Question is: what setting do i turn the switch on my Antenna to as in the picture?..Or does it matter..?
THANKS AGAIN!..
Kevin..

Boatcarpenter · 01-13-2010, 12:41

It seems as though your antenna is working properly. The clicking is it changing the frequency setting to correspond to the frequency you are setting on the radio to transmit and/or receive on. Look at the pointer and remember where it is set and then change frequency on the radio until it clicks and then look to see if the pointer has moved. If it has, then I think all is good.
I'm no expert on this subject, but I think I am correct on this.
BC

wsucougarx · 01-13-2010, 15:02

The clicking is normal

Your antenna is a "matching antenna". The Antenna unit automatically adjusts according to your freq on the 524

Irv · 01-13-2010, 15:27

The MX6707 antenna is actually a vertical dipole, fed in the middle, where it screws together. The base unit is a matching network with several positions. Depending on where you set your frequency in the 30 to 80 MHz band, it will click in one of several tuning networks designed to translate the odd, complex impedance to standard 50 ohms, or close to it. Caution: Never ever try to turn that rotary switch backwards. It has a direction arrow and must always be obeyed. It is a rotary stepping switch inside that acts as a ratchet. You will break the knob or damage the switch if you go backwards. Seen many like that. The only reason they even put it there is so that if your control cable breaks, you can manually select the proper network for your intended frequency. Otherwise, leave it alone. The frequency is printed on the 6707 next to the switch.
The reason that they went to the vertical dipole instead of a simple vertical is that this antenna needs no ground plane to operate properly. A simple vertical antenna uses either a vehicle body or a few ground radials to work against to get the electric fields arranged right for effective radiation. Since these antennas are generic to a multitude of vehicles, they cannot know in advance how to configure the tuning networks. By going to a vertical dipole where the fields from the top end on the bottom section, the behavior is far more predictable and that means they can just grab this antenna system and install it anywhere on any vehicle, tied down or not, and it will work reasonably well. Not so with a simple vertical antenna.
As for receiving TV, you're a few months too late. Analog TV on channel 2 used to be able to be received. Not anymore. Irv

Irv · 01-13-2010, 15:31

I should elaborate on the feed point. The radio coax cable goes to the base unit, where it uses various coils and capacitors to match the antenna. The output of the matching network feeds into a very small coax cable that then goes up through the middle of that big spring to the fat threaded base of the lower section. Look inside and see the center pin and a ring. That carries the coax signal, center and braid, up inside the lower section to the top of the lower section. There, the braid connects to the lower section and the center connects to the upper section. The bottom end of the section is actually insulated from the big fat connector or the spring. Some people gut the MX6707 and install new parts to use it as a CB antenna. Irv

jwaller · 01-13-2010, 17:14

all normal all good. you can buy a little later model of the same antenna that automatically tunes itself. if you don't hear the clicking then don't transmit after channel swapping. lots of times in the cold the motor will snap it's drive shaft and won't properly tune the antenna and burn up your radio.
make sure after you swap stations you hear it retune.

jatonka · 01-13-2010, 23:45

Hello J waller, Can you PM me sometime to say Hi, I have a question. JT

jwaller · 01-14-2010, 08:49

Quote:

Originally Posted by jatonka

Hello J waller, Can you PM me sometime to say Hi, I have a question. JT

sure thing.

decodeme2 · 01-17-2010, 03:04

Thanks guys,
I understand it now!..All i need now is a "heater" to double my distance!..
Kevin..

86humv · 01-17-2010, 22:57

The sincgars AS-3900, or AS-3916 antennas can be used also , they don't need to be tuned...its automatic.