High SWR: Exterminator antenna. Help.

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Marcos
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High SWR: Exterminator antenna. Help.

Post by Marcos »

Hello. I have purchased 3/4 Exterminator antenna (500 W) tuned (instructions are not included). But when i have installed the antenna SWR is too high. For example, 30 watts in transmitter are 7.4 Watts reflected power (too high!!!). Cable is Microwave (high quality). Transmitter is Suono ESVA. Antenna mast only 5 meters.

With this high reflected power, transmitter is in danger. What can i do?

Thanks!

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pcs
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Post by pcs »

1. Please note that antenna is not extended when shipped. This is of course due to the size.
Extend the top section until you reach the black marker, than fix it there. Middle section is just inserted and fixed.

2. Also keep in mind that installation can affect the SWR of the antenna. This means it is recommended that you check swr and if needed adjust it slightly. Any necessary adjustment will be small.

3. Do not measure SWR with internal power/SWR meters, these are only rough indicators. No radio station should exist without SWR meter, use one or antenna analyzer to measure your SWR. When performing adjustments/measurements on your antenna with SWR meter do not use full power. Use only as much as necessary to perform the measurement. Of course the best option is to use antenna analyzer, either MFJ or rigexpert.
One of the advantages of analyzers is that you don't even need transmitter to make measurement.

http://www.pcs-electronics.com/mfj269-h ... p-731.html
http://www.pcs-electronics.com/graphica ... -1553.html
Best regards,
Marko - PCS Electronics
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Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Marcos
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Post by Marcos »

I've extended antenna and now reflected power is about 1%. My transmitter is now safer. For now, i think this is enough for me.

Many thanks!
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pcs
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Post by pcs »

That is perfectly normal, have fun.
Best regards,
Marko - PCS Electronics
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http://www.pcs-electronics.com
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zuzu
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Post by zuzu »

I'm having a similar problem with the Exterminator antenna. As far as I can tell, it's fully extended, but only has two parts. It was tuned to 187MHz (Channel 8 analog television). The antenna was shipped to me without instructions. Are they available online as a PDF? Thanks in advance.
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Post by pcs »

For manual email me/support, we will also put it on the forum under all other products, it should have been there for months, not sure what happened.

Otherwise the installation is fairly simple, you need to extend the sections (usually 1 for tv and 2 for FM) until they reach the ring made with black marker.
We made those marks after we tuned the antenna. Than we collapsed the sections to make antenna smaller for the transport.

After installation please verify SWR with SWR meter. Depending on where you install the antenna (metal objects nearby) and distance from the roof/tower
resonant frequency can move up/down a bit. When checking SWR remember to use minimum power required to perform the measurement. That is, do not
use full power to check swr as you might damage the transmitter. Better yet use the antenna analyzer, with those you don't need to power up transmitter
to measure the antenna.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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