Choosing a FM Transmitter

[jeffl]

What would be a SWR meter that would work for tuning an FM antenna? I'd like to tune mine if the cost is reasonable.

[Scott T]

According to the published spec on the Vanco website.

**** SWR-1 (SWR & Field Str) *******
Impedance: 50-52 Ohms
SWR: 1:1-1:3
Accuracy: + 5%
Meter Sensivity: 300 uA
Frequency Range: 3.5-150 MHz
Antenna: 5" Bar
Dimensions: 6" x 2" x 2-7/8"


******* SWR-2 (SWR ONLY) **********

Impedance: 50-52 Ohms
SWR: 1:1-1:3
RF-Power: 10 Watts, 100 Watts
Accuracy: SWR 5%, RF-Power 10%
Frequency Range: 1.7 MHz to 150 MHz
Antenna: 5-Inches
Dimensions: 6" x 2" x 2"
******************************

The SWR-3 is NOT within the range 1.7 - 30 mhz

Impedance: 50-52 Ohms
SWR: 1:1-1:3
Accuracy: SWR 5%
Sensivity: 200 uA
Frequency Range: 1.7-30 MHz
Connectors: SO-239 UHF Type

********************************

I have call Vanco and left a message for their technical guy. Once I verify that SWR-1 and SWR-2 can be used for tuning a FM antenna, I will post.

[friskybri]

EDM RDS has my vote. I had someone call me and say they heard my station 4 miles away and had to turn down the mw from 100 to 10.

[pdowns]

The antenna is very important and whatever brand transmitter you use, trying to use the supplied telescoping antennae or worse, the short strips of wire that are supposed to be 1/4 wave verticals is a real mistake. Having the antenna indoors is also a bad plan.

I'm really happy with a Ramsey TM-100 antenna. It is a folded dipole inside of a PVC pipe housing. I even painted the bottom half to blend in to the bricks of my house. I mount it outside of a 2nd story window and I get a clean signal with all the range I need.

http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=TM100

Here's a picture. That's an Easy Light Linker to the right of the antenna. From the street this equipment is invisible, even in daytime.

There are suggestions here about SWR meters. IMO, take the SWR money and buy a decent antenna, cut it to the right length and you'll be happy with the results.




Attached files

[Max-Paul]

Scott

I'll take that crow well done and with A1 sauce if you please.

My humblest apology. I did not see that they combined both SWR1 and SWR3 on the same info page. So, I take that back and say that the SWR1 will function to tune an antenna for a FM transmitters as you have stated.

[Scott T]

Max-Paul wrote:

Scott

I'll take that crow well done and with A1 sauce if you please.

My humblest apology.  I did not see that they combined both SWR1 and SWR3 on the same info page. So, I take that back and say that the SWR1 will function to tune an antenna for a FM transmitters as you have stated.

Max-paul,
You got me all freaked out and I went up in to my 120 degree attic and retune my antenna.
1) First purely off of calculations. Then drove around testing range.
2) With my daughter about 2500 feet away. We talked on the cell phone as I made adjustments. Then drove around testing range.
3) With the Vanco SWR-1 meter. Then drove around testing range.
4) With the RadioShack CB SWR meter. Then drove around testing range.

#1 blew chunks
#2 work well considering my daughter is 13 and her girlfriend was with her.
#3 Had the best range.
#4 Was short on range. Most likely due to the reason you stated regarding Fq range. (a bit of a waste of time, but i wanted to validate it's shortcomings.)

****************************
With that being said, I will still post the response from Vanco once I get it.

There is nothing wrong with a wild goose chase ever once and a while. It keeps you in shape. (or in my case sweaty)

[JamesWright]

All of you have me convinced that the EDM-RDS is the way to go. I am currently using the Ramsey FM30 (last year was my first year). However, I want to add RDS capability. It looks as though the EDM-RDS kit is the way to go. I am going to order it right now. I will let you know how it goes. Wish me luck.

[Scott T]

Scott T wrote:

With that being said, I will still post the response from Vanco once I get it.

I heard back from Vanco and forgot to report back. Vanco confirmed that the SWR-1 is within the range to test FM transmitting antennas.


As far as the EDM with RDS. . .
I got great range and then turn it down to the 10mw setting, only lost about 1/4 of the excellent range I had. WOW what a great unit.

Jim, you will be happy once you receive it. (shipping took 10 working day, so be patient)