Reception Difference

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Volfirefighter

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I have 2 Uniden analog scanners attached to the same attic-mounted scantenna. They have equal lengths of RG6 coming off a good quality splitter and the same F to BNC pigtail.

On the same VHF repeater about 20 miles away:

The BC780XLT gets 4 bars

The BCT15X gets 2 bars

Why so much better receive on the older scanner?
 

JamesO

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RSSI is really a "relative" indicator. But the 780XLT may also have different IF filter bandwidths and has always been considered one of the better analog scanners built.

You may also want to swap the inputs to see if there is a difference between the 2 radios and also try and determine if the signal fades on the 15XT before the 780XLT. You may need to use a variable attenuator for this test?

Again the signal bars are "relative" and may not accurately reflect the actual signal level reaching the scanner and also required to make the signal "full quieting".
 

ofd8001

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Thinking of all possibilities, and you can see if this is the case by swapping inputs as JamesO suggested, one of the pigtails may have a funky connection. Sometimes when cables are made up, there isn't the best of connections.

I'd also suggest seeing what values you show by connecting just one scanner at a time. They say that running two scanners off one antenna may not be the best method - signal could be robbed from one to the other.

There are multicouplers available which are made to connect multiple scanners to one antenna. These devices have, I understand, some type of RF amplification circuit.

We used a multicoupler at our fire station as we had several scanners running from one antenna mounted on a tall tower. It was fed with real good cable.

At home, I have a couple of scanners in my garage. Each has its own antenna in the attic over the garage. I figured that it was cheaper to use two antennas than to buy a multicoupler. If I had more scanners, then I'd run the finances to see whether a multicoupler would be a less costly endeavor.
 

WA0CBW

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There is no "standard" as to how much signal it takes to make a "bar" on the signal strength meter. So 2 bars on one scanner might be the same as 4 bars on another. The bar meters are not calibrated signal strength meters.
BB
 

n4yek

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Apr 20, 2004
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Newport, Tennessee
While this is a different type of radio, the issue is the same.
I used to work for Ten Tec, a ham radio manufacturer, and we would hear people telling us that our receivers were weaker than the Japanese competitors. It was a totally visual perception because of how we set the 's-meter' compared to how they done it. We had a set signal source that we used to set an 'S-9' reading and the Japanese used a lower signal to set an 'S-9'. So when their radio saw an s-9 signal, our radio only saw an s-7 signal. hence some people thought their receiver was better than ours.

That being said, older uniden scanner did seem to receive better. My 780 will receive things way better than my 396T does.
 
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