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Reviews For: PAR SCANNER INTERMOD FILTERS

Category: Filters, RF: bandpass, duplexer, lowpass, highpass, RFI/EMI

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Review Summary For : PAR SCANNER INTERMOD FILTERS
Reviews: 41MSRP: 74 USD
Description:
These scanner filters are used to eliminate interference from high powered pagers and channel "skipping" from other frequencies. The filters are designed to eliminate specific offending frequencies.
Product is in production
More Info: http://www.parelectronics.com/scanner.php
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00415
73383 Rating: 2007-12-30
Very Good Product Time Owned: 0 to 3 months.
I purchased a new Yaesu VR-5000 wideband receiver and was immediately disappointed in the quality of the receiver front-end. I presently use it to monitor the aviation VHF and UHF bands of 118-137 MHz and 225-400 MHz.

Whereas all my other receivers work fine with my outdoor Diamond D130JN discone antenna, the VR-5000 receiver had serious overload and intermodulation problems from FM stations. I was receiving local FM stations all over the VHF and UHF bands. The resultant noise was so bad that I could not squelch it without using the receiver's built-in ATTENUATOR. Of course, this ruined desired signal reception.

This problem led me to PAR Electronics and I purchased one of their VHF-FM Broadband 88-108 MHz filters. Prior to ordering, I checked the FCC's FM Radio Database Query site at http://www.fcc.gov/mb/audio/fmq.html using the "Stations Within a Radius" query form. This searches for stations within a specified distance of your specified coordinates. The query response lists all licensed FM stations and their distance and azimuth. The closest and most powerful station was at 101.3 MHz, 2 miles away.

I ordered the filter and specified the notch to be set at 101.3 MHz. This is a nice feature of the PAR Electronics filter - you can ask that it be tuned to specific frequencies (within technical limits) at no extra charge.

When I received the filter, it included a brief specification sheet and a stopband response printout. This filter actually has three notches in the FM band. In my case, the notches were 90, 98.0 and 101.3 MHz; the notch at 101.3 was about -49 dB with respect to response at 120 MHz.

I installed the filter and it solved the interference problem. I can now set the squelch normally and receive aeronautical stations quite well. I occasionally hear interference on a few frequencies but it seems to come and go, and the frequencies in question do not seem to be active in my area.

My only complaint about the filter is there is no convenient way to fix-mount it to a panel. The filter is designed to plug right into the BNC-F connector on the receiver. The filter comes with a BNC-M on one side and BNC-F on the other - this makes it easy to cascade more than one filter if necessary. While this is somewhat convenient, it does mechanically stress the receiver connector. I asked Dale Parfitt at PAR if I could drill and tap the filter body but he indicated that the material was a relatively thin brass extrusion and not really suitable for that. He said that on future filters he could accommodate any mounting pattern I need. This is another nice thing about PAR - the personalized service and quick response you get, something missing from many companies these days.

It's too bad the VR-5000 receiver designers did not build a good front-end, but it's good that PAR Electronics makes a filter to compensate for it.
MACKAN Rating: 2007-12-07
Another happy customer! Time Owned: 0 to 3 months.
Enlish is not my first language, so this review is a bit short!

I needed a notch filter to attenuate a very strong signal at 167 MHz. The signal was over 9+40db.

I found the PAR website after a few searches on google, and after a few emails I placed my order.
I ordererd a notch filter for this particular frequency, and also a FM-broadcast filter.

Dale was very helpful, and replied fast to my many questions by email.

Shipping to Sweden (Europe) was pretty fast, I got my filters after 10 business days.

As for the 9+40 signal, it is totally blocked now. The signal meter is not even moving.

Thumbs up for Dale and PAR filters!
K6SAT Rating: 2007-11-13
High quality and cost effective filters. Time Owned: 0 to 3 months.
I moved recently into an area that has nearby strong FM broadcast transmitters as well as pager towers. My reception on my scanner was horrible until I installed a VHFSYM158HT to get rid of a pager frequency and a VHF-FM to rid myself of the FM broadcast signals. What a difference, now everything is clear with no interference.

I ordered mine with N connectors and got them within 1 week.

Construction is high quality - you won't be disappointed.
OCEANS777 Rating: 2007-08-29
Outstanding performance and service Time Owned: 0 to 3 months.
My purchase last week of a PAR Electronics VHFSYM162HT filter is easily the best and most rewarding money I have spent for monitoring in a long time. It has turned out to be as important as my antenna and has provided the largest performance gain.

I live only a few miles from a NOAA broadcast tower and all of my receivers/scanners were picking up 162.550 all through VHF and UHF. Searching was essentially useless as was any scanning of air bands and UHF in particular was a mess.

I called PAR and had the pleasure of speaking with Dale about the problem and after listening to my details and questions he explained the effects of the signal on the receivers and suggested a VHFSYM162HT notched at 162.550.

It arrived quickly and I was very impressed with the build quality and appreciated the performance chart that came with it. These filters have the feel of a professional test instrument and are rock solid without being bulky or heavy.

The performance is absolutely outstanding. It has completely eliminated the problem without any degraded performance anywhere else. I can finally hear even distant ATIS frequencies that were not there or just NOAA weather before.

A spectrum sweep shows the true sharpness of the VHFSYM162HT filter in attenuating the offending 162.550 and this is the true beauty of these professional-grade filters; they are sharp enough to defeat the unwanted signals without dragging down desired adjacent signals too.

I am so impressed I ordered the VHFSYM152 and 158 filters today to deal with paging.

You won't beat the performance and pure quality of these filters at anything within hundreds of dollars of the price. (If you could even find anything) Add the ability to specify the frequency you need notched and Dales expertise - it's the last of the true bargains.

In my case it has allowed me to regain the full performance of a discone mounted up high in tough RF environment without suffering the intermod that frequently cripples and 'deafens' the receivers.
N8905W Rating: 2007-04-12
Excellent Performance! Time Owned: 0 to 3 months.
This is a review of Par Electronics and their VHF-FM Scanner Filter.

I had need for a FM filter when I discovered my new scanner(Pro-97)
was receiving 92.9 FM in the airband frequencies. I researched and found
that Par Electronics, among others, was manufacturing such a filter.
It was within that research that I found Eham.net and the positive reviews
on Dale Parfitt and his company, Par Electronics. Those
positive reviews influenced me to contact Dale for my solution.

I am very glad I chose Par Electronics.

Dale is a professional who embodies the passion of electronics
and amateur radio. This passion extends into his products and
is evidenced by the impeccable workmanship and precision tolerances
that went into building my VHF-FM Filter.

The VHF-FM filter was promptly built and promptly shipped in a sturdy box
with careful and well thought out packaging that insulated the filter
from shipping damage.

Inside the box was my filter, invoice and the plot graphing the
actual tested and measured performance of my filter. Terrific!

The filter itself was impeccably constructed using hardy and durable
materials. A real showcase of workmanship in finish and order.

The filter attached to my scanner easily and looked good as well !

I turned the scanner on and immediately started reaping the benefits
of my decision and Dale's work.

There for all to hear were the once impossible lower airband freqs.
There was a large, noticeable improvement in the audio clarity of
all frequencies that I monitor including Milcom, Police, Fire, Ems.
Weak signals now broke squelch and were received with clarity.
As important as anything else, the irritating squelch tail was gone!

I got more benefits than I expected, and Par Electronics got a
second order from me.

If you have need for a radio filter, give Dale and Par Electronics
your strong consideration.

Thank You, Eham.net and Thank You previous reviewers for encouraging
me to seek out Par Electronics!

Mike
n8905w
WB1AFC Rating: 2005-03-23
FM Broacast Band Filter - VHF-FM and UHF 471.25 Custom Filter Time Owned: 0 to 3 months.
WOW… These PAR filters work GREAT!

I recently purchased 4 Radio Shack PRO-2052 scanners to use with my computer controlled scanning setup. The 2052 has RS-232 control with a DB15 on the back panel making it ideal for computer controlled scanning. It is an older model (on close-out pricing) and can be purchased on sale now for $150.

The problem is that the front end is wide open and is subject to significant intermod interference problems, especially after I connected to a discone antenna mounted on my roof at about 40 foot high.

When I connected the discone to my old HP141 Spectrum Analyzer it was easy to see what the problem was:

1. TV Channel 14 is blasting at 471.25 MHZ – Loudest signal I can see from 0-1250MHZ
2. FM Braodcast Band – Second Loudest
3. Pagers at 150 something MHZ
4. Pagers at 462 MHZ

I googled on notch filters and after searching through lots of sites listing very expensive solutions I finally found what looked to be a good solution at a company called PAR Electronics. (http://www.parelectronics.com/) I talked with Dale W4OP at PAR and explained my problem. He immediately understood my problem and made some recommendations as to how a PAR filter could help.

First he recommended starting with a custom filter tuned at the 471.25 frequency to knock out the loudest signal which was causing problems for me on the public service 462MHZ band. Second their off the shelf VHF-FM filter could help with the poor reception I was getting on the 118-136MHZ air band. I am a pilot and this is the band I tune around most.

Both filters arrived in a couple of days after ordering (PAR takes PAYPAL payments making it very easy to do business on-line with them).

The first thing I did was to put the filters in-line and plug my discone back into the spectrum analyzer, and had a look at 440-480MHZ. All I can say is WOW. The TV channel was gone while the police frequencies at 460MHZ were just as loud as ever.

Next I took a look at the 88-108MHZ FM band with and without the filter. Again, the signals all but disappear from the spectrum analyzer. I then fired up my scanner and gave it a try on the air band. Incredible! What a difference! The radio is all but unusable without the filter. When I put it in line I can hear signals that I coulden’t even hear with out it. The FM broadcast band was overloading the front end so much that it was blocking all but the loudest signals.

I will update this review after I have had a chance to test the filters with other radios and in a mobile configuration.

More to come…

Jim
WB1AFC
WB2TPS Rating: 2004-07-01
Terrific! Time Owned: more than 12 months.
Inter-Mod was killing my FT-8000 on 2M. The PAR filter cleaned it up.
I decided to give it the "acid test"
Using a 2M radio in NYC can be hopeless. It is inter-mod alley.
I put the FT-8000 and PAR filter in the car and drove towards Manhattan. As I approached the skyline from the LIE, I waited for the radio front-end to crumble. To my delight, the filter worked!!!

Jim
WT3844 Rating: 2004-07-01
GOOD PRODUCT Time Owned: 0 to 3 months.
AWESOME PRODUCT MY BC895XLT AND 780 XLT WERE FILLED WITH INTERMOD AFTER I BEEFED UP MY ANTENNA TO A TUNED ONE AND UPGRADED MY COAX TO RG8U THEN I ORDERED THE PAR VHF SYM 152 WOW RETURNED MY RADIOS TO SUPERB PERFORMANCE COMPLETELY GOT RID OF 90 OERCENT OF MY INTERMOD PROBLEMS MY 895 WAS ALMOST USELESS BEFORE THIS FILTER NOW I AM USING IT ALMOST AS MUCH AS MY 8500 AND BC780 THIS IS A SUPERB PRODUCT AND DOES WHAT PAR SAYS ALSO MY RANGE HAS INCREASED A LOT THANKS PAR
JACK11 Rating: 2004-02-25
VHFSYM152 Time Owned: 0 to 3 months.
I received a PAR SYMVHF152 intermod filter.Iwas having big problems with inter mod on all of my scanners.This filter really did the trick.Took it all right out.Plus i wanted a Type"N" and a BNC connectors and they took care of it.The filter is proffesionally built and very well put together.Highly reccomended.If i have to buy another filter it will be thru PAR.
WPYI784 Rating: 2003-11-28
VHFSYM162.4 Intermod Filter Time Owned: 0 to 3 months.
My local NWS freq of 162.475 MHz was showing up in frequencies from 155 Mhz to 170 MHZ on a BC780XLT scanner. A few months ago it was sugested on the Strong Signals site (www.srtongsignals.net) I contact Par Electronics for a notch filter. The recomendation was spot on.

After reviewing their web site (www.parelectronics.com) I emailed an inquiry and received a response from the owner Dale Parfitt W4OP. Great guy, I have never contacted a business whose owner checks his email so often. If you send in an inquiry you WILL get a prompt response.

I was finially able to order a model VHFSYM162.4 notch filter last week. I was not disappointed. Opening the box I was reminded of my Stridsberg Multicoupler. Build quality is first rate. It makes you feel like you just purchased a truly professional grade piece of equipment. The filter I purchased provides an attenuating notch of -43.38 dB at 162.47 MHz. Attenuation at 160.07 Mhz is only -2.99 dB and at 165.35 MHz attenuation is only -3.06 dB. That is a steep notch to me.

It solved my overload problem!!

Beats the heck out of having 20+ channels on my scanner using the built in -10 dB attenuator. I placed the filter ahead of the Stridsberg multicoupler that feeds my Pro 2004, BC895XLT, and BC780XLT scanners. According to Dale the insertion loss at 800MHz is .5 Db or less. I cannot see any negative effects on the 800 MHz trunked systems I monitor. Indeed without the front end overload it appears the overall sensitivity of all three scanners has improved.


Great Guy. Great company. Great Product.