PRO96 and 700 MHz (again)

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PRO2006

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I searched and found it mentioned that if you have the extended freqs enabled, and the control is 800 MHz, the PRO96 will let you hear the 700 MHz voice channels.

Can someone confirm this? Smoky Hill is an example tower where you might see this happen. I could log or watch freqs all night, but has anyone seen a 700 MHz freq displayed and heard the audio while it was tracking an 800 CC?

I understand that if the CC is 700 MHz it won't work.

I am also thinking the 700 MHz voice channels are only used when the system gets real busy, and then it overflows into those channels.
 

jimmnn

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700MHz is not only an overflow some agencies are set to use those freqs as primary such as on Smoky Hill for example when you are logging you will see the 700MHz freqs full with Cherry Creek, Douglas County and Littleton Schools especially during morning and afternoon school bus drive time.

Jim<
 

PRO2006

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I monitored Smoky Hill and Zap this morning. I did not see any 700 MHz freqs pop up on the display, only the 800. There should have been 700 MHz traffic on Smoky Hill this morning.

I checked and my extended frequencies are enabled.

So unless somone confirms otherwise, I don't think it works. From what I can tell, it tracks the 800 fine but does not even tune down into 700 MHz freqs when the CC says they should be active.
 

cstockmyer

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I have a really dumb question that I have been meaning to ask for awhile. If my scanner can get the 800 band just great, why is it that it can't get the 700 band too? Seems like if it can get the high band like 800, 700 should be easier. Can someone explain it to me in easy to understand english?
 

ka3jjz

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The answer really is simple - they're not designed to cover these bands. While Win96 might unlock those frequencies, it doesn't mean the scanner will perform well there.

It's exactly the same issue if you were trying to force these scanners to do UHF milair. You might get one that performs well, you might not - and it should not be considered defective if its deaf as a stone here.

If you want reliable 700 Mhz coverage, get one of the Uniden or GRE digitals - simple as that.

73 Mike
 

cstockmyer

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ka3jjz said:
You didn't say anything in your message about which scanner you're using or talking about. If you are talking about the PRO-96 or 2096, the answer really is simple - they're not designed to cover these bands. While Win96 might unlock those frequencies, it doesn't mean the scanner will perform well there.

It's exactly the same issue if you were trying to force these scanners to do UHF milair. You might get one that performs well, you might not - and it should not be considered defective if its deaf as a stone here.

73 Mike
Sorry Sir, yes I was talking about my Pro 96. I guess I am still confused. If a scanner can get the high 800 bands..in my mind the 700 band should be easy. But thanks for taking time to respond!
 

PRO2006

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cstockmyer said:
I have a really dumb question that I have been meaning to ask for awhile. If my scanner can get the 800 band just great, why is it that it can't get the 700 band too? Seems like if it can get the high band like 800, 700 should be easier. Can someone explain it to me in easy to understand english?
You hijacked my thread!!...;)

It might be difficult to explain in laymen's term. It is really the scanner design and what bands they want target during the design process.

So externally coming into the scanner, you could be looking at 118 MHz aircraft, VHF police, 800 MHz, or even higher. That is a very wide band....25 MHz to 1300 MHz. Now they could design a scanner to cover that whole frequency range but there would be tradeoffs in performance and cost.

I work with receivers that cover 100 MHz to 3 GHz with no gaps, but they cost $18,000 dollars!

So to bring the cost down and get good performance, the scanner manufactures break up the RF spectrum into smaller bands. Look at the back of your PRO96 and see those bands listed.

When they break it up into bands inside the scanner, they must also design filters for each band they support. They design the filters to give the best possible performance in whatever band you are listening to, and still keep the cost of the scanner down.

The internal filters are why when you go "out of band" (like trying to listen to 700 MHz on your PRO96) that your performance drops way off, or is not there at all.

A good way to understand filters is to think about an antenna. I have an 800 MHz yagi antenna on the roof. The antenna is designed to pick up signals between 800 and 900 MHz. What I get is really good reception between 800-900, but not so good at 400 MHz, and terrible at 25 MHz. The filters in your scanner work the same way.

The new scanners that cover the 700 MHz band changed the way they do internal frequency conversions, or were able to design wider band filters, but still kept the cost down and gave good performance.

Clear as mud now?
 
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