New Here and I have a transmitter question

[stratocaster]

I recently bought a CZE-05B but I'm a little surprised at the range and want to know the best way to turn it down.

My intent with this transmitter was to have a private radio station for family and friends within ~700Ft of my house, but now it looks as though I should have bought one of those 20mW jobs. I just didn't think it would reach more more than a couple hundred feet so I went up just a smidgen and got the 05B. At 100mW the range is a half mile and at 500mW it reaches a mile or more. I'm not broadcasting anything odd but since it's just for a select audience I don't care to have the whole town listening.

I built a half-wave dipole while waiting for the transmitter to arrive but have since switched to the telescopic antenna it came with and still get about half a mile at 100mW, but I don't want to use it.

I'm old school about certain things and prefer an antenna that is cut and matched to a specific frequency to avoid any unnecessary stress on the transmitter, which is why telescopic antennas creep me out just a bit and why I am looking for a safe way to turn it down. 

Any ideas?

Great board here folks! You've made me think more than once about wanting to turn it up instead of down.  Actually I think I will. I have a place in the country where I go a few times a year and it's near my old high school. I'm pretty serious about going with 7-15 watts off a good antenna 30 feet in the air.




 

[Deleted]

Most people would be tickled to be blessed with terrain like you and I it seems with micropower FM ;D

What you can do is try a dummy load - a 50 (or 75, if that's what your TX is) ohm, non inductive resistor. A 5 watt carbon composition resistor soldered into an RF connector that fits your TX is suitable for your needs.
(yeah, a 2 watt is cheaper, but with proper power deration for continuous service, a 5W fits the math with a safety margin)

Cheers!

[Kage]

I agree with using a dummy load. If it attenuates your signal too much you can make a "leaky" dummy load with a small whip antenna connected to the center terminal of the dummy load.

[stratocaster]

Yep. That should do it. I'll order a couple and will try one on the dipole. I know they are simple antennas to make but this was actually enjoyable even if it was simple.

I'm sort of a stickler for having the right right parts in the chain and have RG58 to some #12 solid cut to 92MHz and enclosed in PVC. All connections are soldered except for the twist on BNC. Just leaning against the wall it worked much better than expected which is great. If I'm going to have a problem I would rather deal with too much instead of too little. I guess my situation here is odd since I don't want to reach more than a few people, but when I get around to setting up a station back home I won't hold back. The location is about 1.5 miles out of town with flat terrain and very few trees or buildings in the way. I'm hoping a 5W will get me at least 2 miles with a good antenna.

You have a lot of good info on this board. Many thanks for the advice.

[alcyone]

I was using a dummy load. But now I'm using a radio shack adjustable power supply with a ground plane in the attic. When I turn the voltage down the range drops from several miles down to about 700 feet. Even though my transmitter calls for a 6 amps the 2.5 amps seems to work just fine.

[Kage]

Cool that makes sense. Most of the circuits in those all in one transmitters are running on voltage regulators so that when you drop the voltage the important parts like the VCO and digital circuits maintain the same voltage whereas the PA usually is tied to the main power w/o regulation so when you drop the input voltage you drop the PA voltage but not the voltage to the parts that need a constant specific voltage.
There is probably a limit as to how far you can drop the input voltage though before the other circuits start acting funny because a lack of juice.
Sounds like you got it figured out though