Division 5 reception with PRO-197

Greetings. I have purchased a PRO-197 and placed it in the car. I have one as a base at home and have already discovered the overload issue as it will not receive Division 5 traffic with an outside antenna but will receive just fine with a back of set whip. Have a similar issue in the car. I was running it on a 5 Db gain 800 whip and got no reception even with 5 bars on the s-meter. Attenuate did not help. Interesting enough I went to Richmond and it worked great but had to have it attenuated. I am now using a straight, unity gain 800 whip and am at least getting intermittent traffic. Anyone else have this issue and what did they do to solve it. By the way, it would not receive with a multiband antenna either so I don't think using an 800 antenna is the issue. Thanks.

Eugene KG4AVE

I'm not sure if it is an antenna issue. I remember having issues with my Pro-106 with stock antenna in the car when I first got it. But adjusting the settings between roam and multisite might have been what gave me a big improvement in reliable reception. I'll try and check my settings on win500 and report back. Some of the more knowledgeable users may chime in first.

Thanks...I was wondering the same.....there is, on my program, only roam, stationary and off.....will try that and see....thanks
Eugene KG4AVE

RS197/PSR 600 notorious for front end signal overload

Eugene said:

Greetings. I have purchased a PRO-197 and placed it in the car. I have one as a base at home and have already discovered the overload issue as it will not receive Division 5 traffic with an outside antenna but will receive just fine with a back of set whip. Have a similar issue in the car. I was running it on a 5 Db gain 800 whip and got no reception even with 5 bars on the s-meter. Attenuate did not help. Interesting enough I went to Richmond and it worked great but had to have it attenuated. I am now using a straight, unity gain 800 whip and am at least getting intermittent traffic. Anyone else have this issue and what did they do to solve it. By the way, it would not receive with a multiband antenna either so I don't think using an 800 antenna is the issue. Thanks.

Eugene KG4AVE

Click to expand...

Eugene,

RS197 & GRE PSR600 scanners are notorious for front end signal overload. Like you some years ago I found out the hard way. I also use Uniden scanners and never have had a problem with front end signal overload using the same antenna input. All of my base Scantenna antennas are tower mounted. Additionally, like all digital scanners because of internal filtering to prevent/minimize RF intermod, my PSR600's RF input insensitivity is worst than my 996XTs. My original solution was the same as yours using selected individual inserted in line attenuator values.

A few years ago I acquired a Telonic multiple user selectable attenuator box which I inserted in line with the signal input coax cable only to my PSR600. This allowed me to select a combination of attenuator values for acceptable reception for what I was trying to receive. I eventually tired of dealing with the PSR600's front end signal overload issues and relegated it to scanning only STARS Divs 1 & 5 and the Fork Mtn. voice repeaters. Presently my attenuator box is 22db. For some other past radio systems monitored I have had to insert as much as 38db. It's either that or live with the frustrations.

My recommendation is acquire a used RF input attenuator box which typically is expensive new but below is a link to one I saw on EBAY, if still available, should work. Various coax cable adapters/connectors are available from various internet sources such as the one shown below:.

Cables, Connectors & Patch Cables since 1995

JFW Industries Model 75B 001 Push Button Attenuator | eBay


John
W4UVV.

PRO 197/STARS

Thanks for the info. Very good information. Wonder what RF around here kills it worse than in Richmond. A variable attenuator is a great idea but having to run splice it inline between the antenna and radio then having to adjust it as conditions warrant while driving might be hazardous. I was worried that this would happen and should have gone with my gut and gotten another Uniden. Thanks again for the info.

Dealing with scanner realities

Eugene said:

Thanks for the info. Very good information. Wonder what RF around here kills it worse than in Richmond. A variable attenuator is a great idea but having to run splice it inline between the antenna and radio then having to adjust it as conditions warrant while driving might be hazardous. I was worried that this would happen and should have gone with my gut and gotten another Uniden. Thanks again for the info.

Click to expand...

In my opinion it was a serious GRE engineering design deficiency. Both Uniden and GRE scanners have their good and bad attributes and regardless of which scanner model used you have to deal with each model's performance realities.

I proposed a reasonable cost/time effort solution to your problem that should work but you are giving up before you even try it. I assume you primarily are interested in receiving STARS Div 5 when mobile. Your scanner antenna probably has a BNC male connector. The attenuator box mentioned should have BNC female chassis connectors on both ends. You connect the BNC male antenna connector to the left side of the attenuator box. You order a 3 ft. double male BNC cable and connect one end to the right side of the attenuator box and the other end of the coax cable to the RF input of your 197. Power up and scan only Div 5 STARS Chesapeake site and select the attenuator box setting combinations for the least attenuation which displays the "T" solid every time it scans the Chesapeake STARS site. You do not make any attenuation change when driving. As long as your driving is within that site's primary coverage area your reception should noticeably improved. What is so difficult about that?

Nothing ventured nothing gained.

John
W4UVV

PRO-197/STARS.

Very true.....I will take a second look and see how it works out. Thanks

Eugene KG4AVE

I live in Suffolk (Driver) literally under the footprint of every TV transmitter site in Hampton Roads and NOAA Weather KHB37 (a "gallon" at 162.55mhz)

STARS is a no-go where I live as is Isle of Wight County and virtually everything else VHF.

I tried attenuation, simpler antenna options and nothing worked.

I bought a $4 FM trap at Radio Shack for $1.99 on clearance, a couple of F to BNC connectors and had some short pieces of coax with BNC connectors in the junk drawer.

I can now copy 5/9 the Hampton and Chesapeake STARS sites, Isle of Wight County (including their simplex freqs) if I enable attenuation on those respective frequencies or TRS. I notice no decrease in performance of the UHF frequencies or the 800 mhz. trunk systems I monitor (Suffolk, Portsmouth, Chesapeake, Newport News).

I know some experts are gonna chime in about "impedance mismatch" and everything else. However, were talking about a consumer grade receiver and nothing more. In no way will this hurt your gear.

After 40 years of Amateur Radio I'm game to try about anything once. It worked for me and it just might help you too..

I know your situation is mobile and not fixed operation but you never know??

73
de
chris
kq4z