Anyone using PAR filters with GRE 500/600?

[eorange]

I know about PAR filters and how good they are. Just curious if anyone is using them with a PSR-500 or PSR-600.

I get FM radio station intermod on the VHF airband freqs, and NOAA radio intermod (there's a transmitter pretty close to me) on the higher VHF bands on the PSR-500. I am considering buying both of those PAR filters.

Anyone a) noticing this problem on the GRE, and b) using a PAR filter?

[hoser147]

eorange, what antenna are you using, just curious as I have a 600 on the way Thanks Hoser

[eorange]

Hoser, I get hosed when using my Diamond Discone, outside and up about 25 feet.

When using the PSR-500 with a whip (Diamond RH77CA, or Maldol AL-500), I get no intermod on the VHF airband, but lots of squelch pops and generally unusable scanning - which I'm betting is caused by the same overload problem.

[trooperdude]

Discones are ultra-wideband and pull in all the garbage.

Try some band-specific antennas and you may not need as many filters.

[eorange]

Thanks, but I'm not looking to change antennas. My other radios do fine with the discone. Just looking to improve performance on one (or 2) specific radios.

[marauder6]

Bumping this thread up.

Anyone using these with good results in lowering the VHF overload issue?

I hooked my PSR-500 to a new RS 20-176 antenna at 25 feet a few days ago, and have had to attenuate all the VHF hi public safety freqs in order to even hear local repeaters. Kinda defeats the purpose of a mast mount.

I have a FM tower about 2 miles from here pumping out 50kw and wonder if the FM trap would work.

[timjude]

Originally Posted by marauder6

Bumping this thread up.

Anyone using these with good results in lowering the VHF overload issue?

I hooked my PSR-500 to a new RS 20-176 antenna at 25 feet a few days ago, and have had to attenuate all the VHF hi public safety freqs in order to even hear local repeaters. Kinda defeats the purpose of a mast mount.

I have a FM tower about 2 miles from here pumping out 50kw and wonder if the FM trap would work.

I use a fm trap works great as i have a fm station close to me it's a 20db

[rankin39]

The Par filters are especially good for a relatively deep, but very narrow, notch when the problem is 152 and 158 MHz. pagers or particular TV channels. I have found that much less expensive filters work just as well for the f.m. broadcast band. Radio Shack has discontinued theirs (I have an old one and it works well) but Scanner Master has a combined f.m. and h.f. filter that also works well at around $25. It's too bad that there isn't a relatively inexpensive filter that takes out ALL f.m. broadcast and TV. That's really what the PSR-500/600 needs. My Par filter for Ch9 TV works really well.
Bob, w0nxn

[somme1916]

Originally Posted by rankin39

The Par filters are especially good for a relatively deep, but very narrow, notch when the problem is 152 and 158 MHz. pagers or particular TV channels. I have found that much less expensive filters work just as well for the f.m. broadcast band. Radio Shack has discontinued theirs (I have an old one and it works well) but Scanner Master has a combined f.m. and h.f. filter that also works well at around $25. It's too bad that there isn't a relatively inexpensive filter that takes out ALL f.m. broadcast and TV. That's really what the PSR-500/600 needs. My Par filter for Ch9 TV works really well.
Bob, w0nxn

I posted this on another thread & it may help here.

Before trying that PAR filter you may want to try what I did on a much earlier Uniden scanner with intermod probs. Radio Shack sold this deal that went in between the antenna & radio. It had a little turn knob on it that , I guess , attenuated the incoming sigs. It was dirt cheap & really did the trick. The good thing about it was you could fine tune it so's not to knock out what you were looking to hear.

I'm not at all sure RS still sells these units but if they do they may be perfect for the new GRE's.

Rob

[mtindor]

Originally Posted by rankin39

My Par filter for Ch9 TV works really well.
Bob, w0nxn

I have a few sources of overload. I think the strongest is our own Ch9 TV station in Steubenville OH which is on an 800+ foot tower and already near the highest ground elevation in the county. It is about 7 miles away. I can hear it by itself and often mixed with other sigs like local paging xmitters and NWS out of Pittsburgh on VHF as well. I must get one of those filters for CH9.

mike

[NDRADIONUT]

I Just Made One That Took The Hash Right Out Of My PSR-500 !!
Started At 35" Of Cable Coax For The Stub And Cut Off An Inch At A Time Until I Was Hashless... Ended Up 27" From The Edge Of The F Connector.
Taking The Length And Velocity Factor Into Acct. Id Say Its Tv Ch 4 That Was Doing It........

[mtindor]

Originally Posted by NDRADIONUT

I Just Made One That Took The Hash Right Out Of My PSR-500 !!
Started At 35" Of Cable Coax For The Stub And Cut Off An Inch At A Time Until I Was Hashless... Ended Up 27" From The Edge Of The F Connector.
Taking The Length And Velocity Factor Into Acct. Id Say Its Tv Ch 4 That Was Doing It........

I tried that once last year when I had my 996 and was trying to attenuate either 152 Mhz paging or 190 Mhz TV 9. Either I was doing things wrong or my expectations were too high. It seemed to attenuate everything on VHF and sometimes UHF to some degree, but it never attenuated the frequencies it was 'designed' for to any great extent.

I was making my stubs out of that really cheap RG8 Mini ox RG8 x (whatever the real skinny stuff is that comes in various colors on the outside) - Ya know, the kind you don't really want to run any power through or use above VHF-LO.

I had a BNC T connector on the back of my 996 with the stub on one side and my regular coax from the outside ant coming in on the other side.

Mike

[fineshot1]

I do not use them for scanners but they work real well on my mobile ham gear to filter out the 152 & 158mhz (in one filter) paging stations and also the 454mhz model. They work well and made my mobiles receiver much more stable when traveling in the larger metro areas.

[marauder6]

I don't think it's a 152 or 158 pager issue here as I have tasked my pro-60 and pro-2026 to search those bands the past few days. Very limited pages on those bands. What I experience with atten off is 3 to 5 bars on VHF hi freqs constantly.

I do have a NWS tower somewhere local (KZZ66) at 300 watts. It did mix with local pagers on my pro-60 on a few VHF hi freqs in the past. I don't notice any mixing with pagers on my PSR-500, just overload on the VHF hi band.

I guess I'll try this when it's back in stock
http://www.scannermaster.com/HPN_301.../24-531024.htm

If that doesn't work well, Ill try a Par filter to kill the 162Mhz.

Anybody have an idea how to locate NWS tower sites? The FCC database does not list these.

SMG

[mtindor]

Originally Posted by marauder6

Anybody have an idea how to locate NWS tower sites? The FCC database does not list these.

SMG

KZZ-66 operates 24 hours a day on a frequency of 162.400 MHz. KZZ-66 transmits at 300 watts of power, from a tower located 2 miles northeast of Galesburg.

http://www.crh.noaa.gov/ilx/nwr/nwrgbg.php
http://www.crh.noaa.gov/ilx/?n=nwr
http://www.crh.noaa.gov/ilx

http://www.nws.noaa.gov/nwr/CntyCov/nwrIL.htm

There are two other transmitters that 'cover' Knox Co as well. Look at the link directly above to see the transmitters themselves. Some of those transmitters are 1000 watt and on top of television towers - Entirely possible that one closer to you may be affecting you less than one farther way. Either way you look at it, if you get a filter for 162.4xx range it'll nail em all pretty good heh.

Mike

[mtindor]

I just ordered a PAR filter from Dale. He answered his phone on a Saturday afternoon - I explained what I needed / what sort of xmitters are around. He told me exactly what I need to get, how he'd fine tune it, etc. I had no choice but to order - the man is great.

Mike

[eorange]

So with your mix of transmitters around - what did he recommend?

[mtindor]

Originally Posted by eorange

So with your mix of transmitters around - what did he recommend?

My combination is a combination of overload (TV transmitter close by on ~190 Mhz) as well as intermod usually from the TV9 station + paging transmitter on ~152.48 Mhz + two very close amateur repeaters on 146.94 and 147.06 Mhz.

What is affecting my VHF-HI from one end to the other is the TV station. The intermod from the three sources is at various points on VHF-HI. Knocking out the high power TV station itself may be enough to make everything else happy for the most part.

The typical -3db points on each side of the notch are approximately +-1.5% of the center freq. So to notch 152.48 Mhz there will be 3db or greater attenuation between 150.19 and 154.77. I'm not willing to sacrifice that much spectrum on VHF (I like to listen for distant stations and so I want my sensitivity). I could put out about $1000 and have a much tighter notch, but I don't think I want to go that route Of course, now that I think about it, there probably isn't anything between 150.19 and 154.77 that I want to listen to from a distance... but I'm not ready to commit to that yet.

Since the TV station is the likely biggest offender/problem causer, I should take it out first and foremost. And it's the easiest to take out, because there is nothing I might want to hear at or near 187 Mhz. Then if there are any other areas that absolutely need a filter, that can be addressed later.

Of course my conversation with Dale was not _that_ involved. He knew I didn't want to have significant attenuation between 150.19 - 154.77. On TV9, most of the power is focused on the 4.5 Mhz video signal. He said he'd "center the filter on the center of the video portion and then bias the response for a slower recovery on the high side so that the aural carrier will also be well down on the response curve."

Mike

[woody_46]

I don't have a 500 yet, I have a pro 2096. I had a problem with overload too. A Watson tuneable antenna filter helped me. It tunes 85 to 175 MHZ. I can now use an outdoor antenna with good results, with the attenuator on.

I had a high power FM transmitter causing problems here. I'm not sure how effective it (the filter) might be with multiple sources of overload.

[mtindor]

Originally Posted by woody_46

I don't have a 500 yet, I have a pro 2096. I had a problem with overload too. A Watson tuneable antenna filter helped me. It tunes 85 to 175 MHZ. I can now use an outdoor antenna with good results, with the attenuator on.

I had a high power FM transmitter causing problems here. I'm not sure how effective it (the filter) might be with multiple sources of overload.

It's probably best at the tuned freq and degrades in performance not far from it (i.e. less attenuation), just like a non-tunable deal. But boy that certainly would be a handy item to have when you aren't sure whihc signal is the one that is the most offensive.

Fortunately, and hopefully, I've isolated the one single source that is causing the overload. It was also a participant in the intermod problem. WIth that source out of the way, I'll at least be able to scan all of VHF - I may still run across some intermod between pager system and ham transmitters when they are on, but fortunately they aren't active often. So I'm keeping my fingers crossed. I have no doubt the PAR will do its job. Just hoping that'll be enough to make VHF scannable.

I really do like the idea of a tunable filter just to have around, if the price is right. do you have a model # for that Watson handy? I'm assuming it's probably an older item?

mike