reception problems after grounding

[BuffaloJustice]

First let me say this site has been immensely helpful and I'm glad to be on board. I mounted a RS Discone on my roof and used RG-6qs because I have a full spool and I read here that it would alright for scanning. After hooking it all up I was getting clear transmissions from up to 30ish miles, not bad in hill country. I bought a third scanner and I'm using a cable splitter to connect two of the radios. Signal wasn't noticeably affetcted. Tonight I drove a ground rod and used a grounding block at the entrance. Now all the local agencies, I live within blocks of the repeater, are nearly unreadable through the static but the further agencies sound like I'm in the dispatch room. What is going on here? At first I thought I had too many connectors on a lossy cable, but when the PD thirty miles away over mountains (really steep hills) keyed up I just went numb with confusion, this actually happens alot Is it possible to "overload" the scanner? I drive right by the repeater every day and my mobile doesn't do that. Any help would be appreciated.

 

[mrsvensven]

It is possible to overload the scanner with too much signal. For a start, you can turn on the attenuator for the close signals. That should cut the signal down a little bit and hopefully fix the problem.

 

[buddrousa]

Have you tested the ground point to make sure you are not shorted center pin to ground? What did you use to put in line for surge? Does it show good to center to center and shield to shield? Just some ideas.

 

[BuffaloJustice]

Thanks for the quick input guys. A simple continuity test was negative. I don't think the pro 160 has attenuation? No surge pro yet, that was part of the addition of the block, so I can detach it completely and pull the lead back into the house when not in use. I know, it's bad! It's a temp rig up I did kind of on a whim with stuff I had around, except the antenna.

This may be better for another thread but the plan ends with good cable, low loss connectors, line surge pro, a better splitter and much more robust ground and bonding system. I'm contemplating getting into the HAM side, when time and money get better, so I'm willing to go little overkill on this part. What cables and arrestors would you guys recommend? I saw the splitters on the multiple scanner sticky so I'll probably go with one of those, any thoughts there? Again, thanks for the help!

 

[kb2vxa]

When it comes to coax the NEC only requires the shield to be grounded, not a lightning arrestor so a ground block is all that's needed and why the cable company uses them on each drop line. If you get hit an arrestor won't save you any more than a ground block so never mind it, they're only intended to bleed static charge and that won't happen on short elements such as those on a scanner antenna.

You have raised the question of just what you call "static" when there is no such thing on VHF/UHF frequencies to begin with and FM detectors are immune. To be more specific, is something now dragging in RF hash or has your overall signal level dropped so you're hearing white noise on the less than booming local signals?

In either case I suspect an improperly installed connector somewhere, often they look good but may not make solid contact with the shield. While an ohm meter check may reveal a "whisker" shorting to the center conductor unless you're using a Kelvin bridge (milliohm meter) a simple continuity check won't reveal a bad connection, even one strand of the shield making contact is enough to give a "zero" indication on an ordinary meter. Since it appears your problem started when you installed the ground block, cut the coax and put connectors on at that point I suggest you cut them off and start again, then report back as to what results you obtained.

BTW I hope you used the right stripper, crimp dies and connectors for the job, RG6-U quad shield is a slightly different animal from the ordinary.

So many people abuse the term with vague descriptions, probably never heard the song "FM (no static at all)" either.

 

[BuffaloJustice]

As a matter of fact I haven't heard the song. That's good info, thanks. It is very possible to have a bad connector, it was freezing out and I was moving pretty quick. I am a network cabling and hardware tech so I have the right tools and connectors. I stopped using 59 since the limited TV installs I do are for family and friends and usually involve internet so why not go with the better stuff. I am an overkill kind of guy when it comes to cable plants so this install was to be a quick function check.

 

[Sinister]

I would say a bad connector would most likely be your issue as has been already stated.
I had a similar issue after setting my cable up and that was the first thing I checked. I found that the cable run from the grounding block to the radio was shorting to ground, after changing the connector all was good.

 

[n5ims]

Now all the local agencies, I live within blocks of the repeater, are nearly unreadable through the static but the further agencies sound like I'm in the dispatch room.QUOTE]

With the distant signals much stronger, it's probably not a bad connector since their signal would be reduced as well. Most likely you've increased your signal to the point where the scanner is being overloaded on the local signals, causing this issue. This happens quite frequently with the GRE based scanners. Although yours is a Uniden based one, since you're "within blocks of the repeater", this is most likely the issue.

You can get an antenuator ( like one of these --> 565-4108- ) for the local signals and remove it for the others.

 

[BuffaloJustice]

At this point I will wait for the weather to improve then redo the connections. If the problem persists I will look into the attenuator. Right now I am receiving departments from 30 miles out with no problem. Thanks for the help.

 

[kb2vxa]

Yeah, lets wait on the connectors before passing judgment, that seems to be the change that affected the system. Since you never heard the song it's by Steely Dan.

Bury the bottle mama, it's grapefruit wine
Kick off your high heel sneakers, it's party time
The girls don't seem to care, what's on
As long as it plays till dawn
Nothing but blues and Elvis
And somebody else's favorite song

Give her some funked up muzak, she treats you nice
Feed her some hungry reggae, she'll love you twice
The girls don't seem to care, tonight
As long as the mood is right

No static at all
No static at all

FM, no static at all

Give her some funked up muzak, she treats you nice
Feed her some hungry reggae, she'll roll you twice
The girls don't seem to care, tonight
As long as the mood is right

No static at all
No static at all

FM, no static at all

 

[jim202]

Several comments seem to be in order here.

First, you can and will get static on FM. Better go back and check your source of that comment.
Been in the radio field for well over 4o years now and you sure can hear static on an FM
signal. The question comes up of just what your definition is of static. Mine is if you hear
any weak signal the has the typical popping, hiss, modulation almost into the noise floor,
that's static. Have a car pull up behind you on the road at a stop light with some bad plug
wires and you can hear the popping on an FM signal your trying to listen to. Generally you
can be listening to a regular FM station and hear this. You can drive by a power line with
a bad insulator and hear the rise in the noise (static) on the FM radio station your listening
to. There are many definitions of what one calls static. But the bottom line is you can
have it on an FM receiver. I have even seen static problems on 800 MHz receivers.

Second comment here is in improving your antenna system, there is a good chance that
you are now having a problem with a paging transmitter causing an over load problem
on some frequencies. The question that now comes up is just what are the exact
frequencies that your having the problem with and what are the exact frequencies
that got better. My gut feeling is that your receiver doesn't have the selectivity to
keep out strong near by signals. You may be forced to install a notch filter to try
and reduce the signal strength of the offending transmitter.

Jim

 

[BuffaloJustice]

OK so I googled the song and I have heard it. My senior year of high school I had my photography independent study my first hour, which was the teachers free period. He rocked Steely Dan while freestylin' the pottery wheel. Man does that bring back some memories.

It's supposed to warm up a bit in the next couple of days so I'll fix it up and see what happens.

 

[Tech792]

What about your cable splitter? Is it just a splitter or does it also include a preamp? If its one that has a preamp, try turning it off or lowering gain. This could also overload your receiver.

 

[kb2vxa]

"Been in the radio field for well over 4o years now..."
So have I so are we having another global warming/global cooling scenario here? Maybe you never heard that in a room full of engineers no two can agree on anything, meanwhile the technician has fixed the problem and is quietly on his way.

"It's supposed to warm up a bit in the next couple of days so I'll fix it up and see what happens."
The key word here is "supposed" while the guarantee is after a narrow window opens it always closes again and frosts over.

"What about your cable splitter?"
That was before the fact and irrelevant, go back and read it again.

Buffy, (;->) I see the way this thread is going so I'm out of here. PM me when we have something further to discuss.

 

[BuffaloJustice]

"The key word here is "supposed" while the guarantee is after a narrow window opens it always closes again and frosts over."

I just made it, that opportunity lady sure is fast!

OK so I got the connections redone. I scrapped the old ones and took a little time on the new ones, they came out nice. The old ones weren't horrible but they were a little sloppy. I'm having the same problem as before except now I can intermittently hear voices and what sounds like commercials on one frequency. I am picking up the local mobile units from across town, but the main dispatch channel just sounds like a bugg zapper when one of those real big june bugs gets stuck in there. I am now also picking up the mobile units from the town 30 miles south while before I was getting only the repeater traffic.

The splitter is the non powered variety and everything worked fine until I added the ground block.

 

[hoser147]

What happens when you unhook the ground block?

 

[BuffaloJustice]

Funny, I just did that. It gets better on all but two frequencies. I can now hear the nws "ghosting" on one of them. The other is a PD mobile that is really quite.

I snaked a plug off a wall plate and will take the block out next.

 

[blueangel-eric]

"The key word here is "supposed" while the guarantee is after a narrow window opens it always closes again and frosts over."

I just made it, that opportunity lady sure is fast!

OK so I got the connections redone. I scrapped the old ones and took a little time on the new ones, they came out nice. The old ones weren't horrible but they were a little sloppy. I'm having the same problem as before except now I can intermittently hear voices and what sounds like commercials on one frequency. I am picking up the local mobile units from across town, but the main dispatch channel just sounds like a bugg zapper when one of those real big june bugs gets stuck in there. I am now also picking up the mobile units from the town 30 miles south while before I was getting only the repeater traffic.

The splitter is the non powered variety and everything worked fine until I added the ground block.

wow, it sounds like your connections are better now. now you just got to deal with the overload.