detroit simulcast reception in the burbs

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313RADIO

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hey folks, I'm new to digital, and looking for some advice.
I am in the suburbs ( 14 / gratiot area ) and trying to monitor Detroit simulcast
my radio is a pro-2096, latest updates...
The stock antenna on the radio decodes NOTHING, so i got a yagi antenna that is a 806-939 MHz about 15 feet up (http://www.wilsonelectronics.com/ViewProductB.php?ID=13) aimed downtown.
im using RG6 quad CATV coax with N/BNC adapters on the ends...
The audio is broken up so bad it is hard to follow conversations, I would say less than 70% of the audio actually get decoded correctly. The average decode percentage on the Control channel is around 78%

Is this is normal? i am only about 5 or 6 miles from Detroit border...
Are you guys in the burbs having the same problems listing to Detroit?
I am thinking about changing the coax for some low loss LMR... or maybe a higher gain antenna.... what do you guys think?
Besides Detroit Macomb county tunes in OK... (even that breaks up a bit), and warren's systems sounds great.
I remember when Detroit was on analog repeaters, had NO problem pulling them in....
 
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seamusg

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Feb 10, 2004
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Grand Blanc, MI
KD8EYF said:
hey folks, I'm new to digital, and looking for some advice.
I am in the suburbs ( 14 / gratiot area ) and trying to monitor Detroit simulcast
my radio is a pro-2096, latest updates...
The stock antenna on the radio decodes NOTHING, so i got a yagi antenna that is a 806-939 MHz about 15 feet up (http://www.wilsonelectronics.com/ViewProductB.php?ID=13) aimed downtown.
im using RG6 quad CATV coax with N/BNC adapters on the ends...
The audio is broken up so bad it is hard to follow conversations, I would say less than 70% of the audio actually get decoded correctly. The average decode percentage on the Control channel is around 78%

Is this is normal? i am only about 5 or 6 miles from Detroit border...
Are you guys in the burbs having the same problems listing to Detroit?
I am thinking about changing the coax for some low loss LMR... or maybe a higher gain antenna.... what do you guys think?
Besides Detroit Macomb county tunes in OK... (even that breaks up a bit), and warren's systems sounds great.
I remember when Detroit was on analog repeaters, had NO problem pulling them in....
You might want to point your yagi at just one site in Detroit. I believe the closest one to you is at Denby. When I lived in Fraser at 14 Mi and Garfield I could get a 90% decode rate, with a rubber ducky by moving the radio a little till I got a good decode rate. I believe Steve (K8PBX) could get Detroit from 32 Mi and Van Dyke. To receive a simulcast, you want to only get one tower within the subsystem and eliminate the multipath.
 

KB8UYC

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Ypsilanti Michigan
KD8EYF said:
hey folks, I'm new to digital, and looking for some advice.
I am in the suburbs ( 14 / gratiot area ) and trying to monitor Detroit simulcast
my radio is a pro-2096, latest updates...
The stock antenna on the radio decodes NOTHING, so i got a yagi antenna that is a 806-939 MHz about 15 feet up (http://www.wilsonelectronics.com/ViewProductB.php?ID=13) aimed downtown.
im using RG6 quad CATV coax with N/BNC adapters on the ends...
The audio is broken up so bad it is hard to follow conversations, I would say less than 70% of the audio actually get decoded correctly. The average decode percentage on the Control channel is around 78%

Is this is normal? i am only about 5 or 6 miles from Detroit border...
Are you guys in the burbs having the same problems listing to Detroit?
I am thinking about changing the coax for some low loss LMR... or maybe a higher gain antenna.... what do you guys think?
Besides Detroit Macomb county tunes in OK... (even that breaks up a bit), and warren's systems sounds great.
I remember when Detroit was on analog repeaters, had NO problem pulling them in....

Detroit's System was designed to keep the signals inside of the city. You will need a yagi with as much gain as you can get(aford) Second thing to do is pick the closest tower and point your yagi to it. Third thing to do is get real coax, RG6 is 75 ohm coax, you have a 50 ohm antenna. I recommend LMR 400

Hope that helps
 

MOTST

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Agreed! The 75 ohm coax is killing your signal. Change it out to a low loss 50 ohm, and you should have no problem hearing Detroit.
 

iMONITOR

Silent Key
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MOTST said:
Agreed! The 75 ohm coax is killing your signal. Change it out to a low loss 50 ohm, and you should have no problem hearing Detroit.

I wouldn't bet any money on that. 75 ohm vs 50 ohm coax, for scanner radio use makes very little difference. In fact 75 ohm RG6 will have less loss than many 50 ohm coax options. LMR400 is great coax, and would be a better choice over RG6, but it's not necessary, and won't solve this problem.

His reception issues with Detroit have nothing to do with the impedance of his coax. One of RR's members who lives way North of Detroit (Washington Township), is using RG6 75 ohm coax, and receiving Detroit's simulcast system loud and clear.
 
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iMONITOR

Silent Key
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seamusg's suggestion is the most effective. You also need to get it up higher for good results. 25~30' if possible.
 
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MOTST

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With all due respect, matching a 52 ohm device to a 52 ohm antenna with 75 ohm cable is just asking to degrade your signal. Maximum power is xfered when there is a match.
Low loss 52 ohm cable and a yagi pointed toward one of the Detroit tower sub-sites should work fine.
 

K8PBX

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Washington, Michigan
GreatLakes said:
I wouldn't bet any money on that. 75 ohm vs 50 ohm coax, for scanner radio use makes very little difference. In fact 75 ohm RG6 will have less loss than many 50 ohm coax options. LMR400 is great coax, and would be a better choice over RG6, but it's not necessary, and won't solve this problem.

His reception issues with Detroit have nothing to do with the impedance of his coax. One of RR's members who lives way North of Detroit (Washington Township), is using RG6 75 ohm coax, and receiving Detroit's simulcast system loud and clear.

That would be me. An interesting article discussing 75 vs 50 ohm coax for scanners can be found here:

http://www.soundcityusa.net/vintage-electronics-articles/antenna-impedance.html

The antenna impedance presented by a ground plane scanner antenna during normal scanning may range from a few ohms to several thousand ohms. For this reason, 50 ohms is no more desirable than 75 ohms or any other value. Impedance is not a worthy consideration with scanners. The choice of 50-ohm hardware is just tradition.
 
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Jimmy252

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Oakland County, MI
Im continuing to try to find remedies to get the signal here in farmington without buying large antennas. Its not that i dont want to, its that the City Of Farmington wont let me put anything up on my house or in my yard. Its an automatic fine... heck, ive heard they wont let a business owner in downtown farmington put up a new 20'-30' sign for the stores near the old T.J Maxx.

My setup so far is:
Pro - 96
Latest firmware update
RS 800 MHz Antenna
Sometimes Global Attenuation increases the signal


But the odds for me getting a clear signal looks slim, any and ALL suggestions will help, thanks
 
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iMONITOR

Silent Key
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Jimmy252 said:
Im continuing to try to find remedies to get the signal here in farmington without buying large antennas. Its not that i dont want to, its that the City Of Farmington wont let me put anything up on my house or in my yard.

But the odds for me getting a clear signal looks slim, any and ALL suggestions will help, thanks

A Yagi antenna for the 850MHz band is small. Maybe 15"- 24" long, and the elements are a few inches on each side. You could probably hide it along side your chimney. Many people mount them in their attic. Of course you want to get it as high as possible, but if you have a two story home, and put it in the attic, that's pretty high.

You could test it prior to an actual installation. Just take your Yagi, and scanner up into the attic and see how it performs. Although I have to admit, receiving Detroit from Farmington is a stretch.
 

Jimmy252

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I live at 10 mile and orchard lake ( About a mile north of Grn River). At home, signal strength is about 50-80% with a lot of choppiness. However when im in my car and on grand river ave..... reception is great, and thats only about a mile from me. I know grand river is probably a "Line of Sight" between me and a tower because i can see the skyline on a good day. so im pretty sure i can get it if im up high enough.
 

MOTST

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Why would you not match a 50 ohm antenna to 50 ohm feed line?? What is the spec on your scanner (for an external antenna)? Does it say 50 or 75 ohm? Weather you are using a yagi, ground plane, beam, dipole, etc, you MUST match the feed line to the antenna impedance for maximum transfer.
Now, the frequency that the antenna is cut for, is narrow, you might drop off signal from center, but it is still 50 ohms.
 
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