Ramsey fm 100

[goduke21]

I just got the Ramsey fm 100 and love it. The only problem is I wish it could transmit just a little farther. I don't want too much more. I'm currently using the antenna that came with it and using it in my garage. I don't want to spend alot of money either. Any suggestions

[mmais68569]

Try moving the antenna outside the garage & see if that helps any.

Mike

[Scott T]

Build a real antenna and put it in your attic. It doesn't cost a lot, maybe $20-30 plus cabling.

Radio Shack (online) is a great place to order parts. (FYI- if you go to the store and have them order it for you there is no shipping cost)

Key note: Check with Ramsey about the antenna impedance. The cable and sat guys use 75 ohms (rg-59 cable), most FM transmitters use the 50 ohms (rg-58 cable) You'll find that near the police scanners at Radio Shack.

Tuning Equipment - you will want to pick up a SWR meter. This device will measure the transmitting power that get out through the antenna. If your antenna is not tuned correctly, the power can be reflected back into your transmitter and overhead/burn out the first stage circuit.

http://www.radioshack.com/product/index.jsp?productId=2036239


If you don't want to attempt the DYI, then buy Ramsey Tru-match kit.

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

[JBullard]

Scott T wrote:

Tuning Equipment - you will want to pick up a SWR meter. This device will measure the transmitting power that get out through the antenna. If your antenna is not tuned correctly, the power can be reflected back into your transmitter and overhead/burn out the first stage circuit.

http://www.radioshack.com/product/index.jsp?productId=2036239

I would NOT recommend the SWR meter posted in the above link. It is only for 3 - 30 mhz freg range, and would give you false information.

Only use a SWR meter that includes the 88 - 108 mhz fm broadcast band in its specs, there are a lot out there, here it a link to just one example

http://www.hamcity.com/store/pc/viewPrd.asp?idcategory=83&idproduct=204

[Scott T]

Thanks John for the correction. Tossing my Radio Shack SWR.

I found Amateur Electric Supply in Cleveland. They have a low cost SWR that is within the FM band for $30.

But more importantly, I picked the brain of the sales guy and got great information on rebuilding my di-pole.

SCORE!

[JBullard]

Your welcome Scott. Just didn't want anyone to damage their transmitter by using a SWR meter designed for the wrong frequencies and getting erronous information.

Several years ago (when VHF SWR meters were extremely expensive) Mark, K5XLP, posted on a ham radio forum a work around to use a CB radio band SWR meter for tuning 2 meter antennas ( 144 - 148 mhz), I will not share his tip here as someone could easily damage their transmitter if they are were not very familiar with using both 10 meter equipment and VHF equipment.

My safety tip of the day: Always use the proper equipment for the task at hand

[Max-Paul]

Also keep this in mind too. Some of those swr meters have a minimum power requirement to set the meter. I mean C.B.s are what 4 watts? And we are playing with 10mW. I just dont know if that will be enough to excite the meter to full scale in order to "Set" the meter, or calibrate it to forward power before flipping the switch to look at reverse power.

Of course a Bird watt meter with the right plugs is the way to go.

De KF0OX

[JBullard]

All the more reason to read the specs before making a purchase, and be sure of the suitability of the device.

Especially when dealing with Ramsey transmitters. Unless something changed recently, the Ramseys were well known for not being very tolerent of an SWR mismatch, resulting in blown final output transistors.

de KD4JZV

[goduke21]

Thanks for all the help. Alot of the info went over my head. I bought the transmitter already put together from a guy on pc. After looking at the instructions there would have been no way I could have assembled it. I just wanted to get another 200 ft out of it. Also how far up do you turn the line 1 knob. It is only clear sounding if I turn up not even a quarter of the way.

[Max-Paul]

goduke,

at what volume setting is your computer set to? If it is lets say more than 50%, crank it back some and then you might need to turn up the "line 1 knob".

73 KD4JZV DE KF0OX

[goduke21]

If I buy the true match antenna will it improve the sound quality or just improve the range.

[mmais68569]

I had your problem & I turned down the volume on the computer to between 50& 60, & distortion went away.

mike

[Scott T]

goduke21 wrote:

If I buy the true match antenna will it improve the sound quality or just improve the range.

The antenna does nothing more that emit an analog radio wave. The range comes from your transmitting power. Efficiency comes from matching your transmitters to your antenna. You must factor transmitting power, frequency, impedance, antenna type/design and cable length. All these items effect range.

Sound quality comes before the signal is transmitted and after it is received (car radio). Before the signal is transmitted, you must provide an appropriate line level into your transmitter. Most transmitters have line level adjustments for the input. But remember, if you are overdriving the input to the transmitter you can still get distortion. These two areas are most likely the place were you can improve the quality of the sound.

Sound quality also comes from within the transmitter with the stereo encoder. Your left and right channels are encoded into one and then transmitted via the frequency carrier. Your car radio then picks up this signal and decodes it back into the left and right channel. Assuming the car's radio decoder is great, that leaves us with the transmitting encoders. Radio stations spend thousands of dollars on stereo encoders, we are using something slightly less than that. However, I will say most of the units that I have seen here do a pretty good job. You will see a big difference in the small ipod transmitters for your car. These seem to have smaller stereo separation and a flatten sound.

Here is an analogy.
A small water pump next to a pond is your transmitter. The garden hose from the pump is your coaxial cable and the sprayer on the end is your antenna. So depending how big your pump is AND the size/length of your garden hose AND the style of the sprayer will determine how large your coverage is going to be.

All that has little effect on the quality of the water that you are pumping. Pumping sludge, sludge comes out. Pumping fresh water, fresh water comes out. Input is quality.

[Max-Paul]

Once you have done the balancing act between output volume at the computer and the input gain at the transmitter. Then there is the radio position in relationship to the comupter and wire paths. It is possible that the a) computer is sending noise into the audio or power wires going to the transmitter. the radio signal is getting into the audio or power lines. By moving things around the noise can be eliminated. If you where to read some of the post over the past two years that I have been on this forum you would see this come up from time to time. Might need to give it a try. Try moving the transmitter as far as feasible from the computer. Put the transmitter on a higher shelf so that it and the computer are not on the same horiztal plane.