Why the difference

[gusbuster]

So I am getting back to scanning after finding my two scanners from 10+ years ago. Both are using the original stock antennas. They are both portable scanners. The first one is a Grecom PSR-500 and the other one is a Uniden BCD396T (both are digital scanners).

My question is this, Why does the PSR-500 picks up the c.h.p. on the 42.0000 frequencies much better than my 396T? Is it because the antenna on the PSR-500 better tuned than the stock antenna of the 396T?
If that is the case, what would be a better mobile/handheld scanner antenna (sma) for the 396T?
Back when i was starting to get into scanning, if i remember correctly, you have to have an antenna tuned to that band of frequencies. Both scanners do well with the P25 systems but the uniden had trouble picking up the EBRS sytem.
I am a newbie and use both arc 500 and arc 396 software for programming. That is one positive thing of saving your registration keys....at least i didn't have to pay money for the software.

I am open to any suggestions and appreciate any help i can get.
John

 

[dave3825]

Not familiar with the psr or what antenna it came with but can you swap the antenna? In the end, an antenna turned for the freqs being used will perform the best. If you have a nano vna, you can see where the antenna resonates. Different scanners can receive better than others in different bands. My pro 93 and 95’s receive vhf better than my 436 and 200.

 

[wtp]

so use the best radio for reception.
i have 5 older analog scanners and i have one set for the 150/159 band (space station and forestry)
one for 800, basically the five 8tacs in it.
one for the 400 band (dea)
another one for business 150 band.
the thing is, the antenna dictates what goes into the radio.
longer antennas for lower freqs, shorter ones for higher ones.
and one radio has a mix of stuff 150, 400, 800 just to make sure i cover the good stuff
the county is on a 700 simulcast so that is covered by the SDS100.
since it is a trunked system, even a paperclip would work.

 

[BinaryMode]

since it is a trunked system, even a paperclip would work.

-+-+Does not compute+-+-

It doesn't matter what type of trunking it is being deployed. Whether P25, EDACS, DMR, etc, what matters is that your radio has good selectivity and sensitivity along with a proper antenna to hear the frequencies of interest... A trunking system is like a protocol of sorts. It just dictates which channel or channels a user uses at any given time.

The term "trunk" is also used in networking... Like with 802.11Q VLANS.

 

[gmclam]

My question is this, Why does the PSR-500 picks up the c.h.p. on the 42.0000 frequencies much better than my 396T? Is it because the antenna on the PSR-500 better tuned than the stock antenna of the 396T?

It has been "general knowledge" that GRE models favor sensitivity over selectivity and the Uniden models favor selectivity over sensitivity. This is one reason I've been a GRE guy as I am more of a DXer.

If that is the case, what would be a better mobile/handheld scanner antenna (sma) for the 396T?
Back when i was starting to get into scanning, if i remember correctly, you have to have an antenna tuned to that band of frequencies. Both scanners do well with the P25 systems but the uniden had trouble picking up the EBRS sytem.

Apples and oranges. So many considerations, not just the frequency you are receiving. A strong signal from a trunked site does not always equate to a good decode rate. A good decode rate usually means better "reception". EBRCS has lots of sites and you may pick up better from one that is not the closest. I have no issues picking it up from here in Sacramento county on my GRE P25 scanners.

 

[wtp]

-+-+Does not compute+-+-

i knew i should have said repeater system.
just the the county is 50 miles wide, it would be hard to hear units directly.
and i am 3 miles from a tower, so it does not take much to hear them.
at my old house i did not need an antenna at all, being 1 mile away.

 

[gmclam]

Location, Location, Location. Distance is one thing, but elevation is another. You could now be in a hole or high up with reception from multiple towers on that Simulcast system. Signal strength will be halved at twice the distance (keeping other things equal). Then there's interfering sources like cell and paging transmitters. Again getting a strong signal (even with a paper clip) is not the key; the key is a good decode rate on the P25 data. And if it's a Simulcast system there's other factors to consider (more than one signal arriving at your receiver "simultaneously").

 

[FCVPI99]

So I am getting back to scanning after finding my two scanners from 10+ years ago. Both are using the original stock antennas. They are both portable scanners. The first one is a Grecom PSR-500 and the other one is a Uniden BCD396T (both are digital scanners).

My question is this, Why does the PSR-500 picks up the c.h.p. on the 42.0000 frequencies much better than my 396T? Is it because the antenna on the PSR-500 better tuned than the stock antenna of the 396T?
If that is the case, what would be a better mobile/handheld scanner antenna (sma) for the 396T?
Back when i was starting to get into scanning, if i remember correctly, you have to have an antenna tuned to that band of frequencies. Both scanners do well with the P25 systems but the uniden had trouble picking up the EBRS sytem.
I am a newbie and use both arc 500 and arc 396 software for programming. That is one positive thing of saving your registration keys....at least i didn't have to pay money for the software.

I am open to any suggestions and appreciate any help i can get.
John

from what i know the PSR's are based on GRE tuners .. and they have always been a bit better then unidens from what i have found from actual use

 

[gusbuster]

from what i know the PSR's are based on GRE tuners .. and they have always been a bit better then unidens from what i have found from actual use

At least for the gre scanner and c.h.p....i starting to see this . So i agree with you on that....i finally found an sma/bnc adapter....stuck the antenna i was using on the gre...no change on my uniden...used a new antenna i got for the uniden, worked the same.
Now, San Mateo county p25, different story, with my new antenna, decodes faster than the gre and much cleaner sound. Not talking about motor boating sound, just easier to understand.

 

[Ubbe]

Signal strength will be halved at twice the distance (keeping other things equal).

When you transmit and wants to double the distance coverage you'll need to use 4 times more transmit power. For receive and measuring signal strength in dBm it will also be a 4 times difference at the double distance. But for uV, the receive voltage that we amplify, it will be half at a double distance.

To be able to receive at a double distance an antenna needs to give an additional 6dB gain.

/Ubbe