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Scanner / Receiver Antennas For discussion of any type of receiving antenna used by a scanner or receiver base, mobile or handheld.

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Old 10-24-2009, 2:24 PM
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Default Easiest way to boost 800mhz reception

I just need a boost to get a clearer signal to my trunking scanner. Is there anyway to improve reception inside the house with some type of window antenna? I would have no clue how to set up a real antenna. I bought the radio shack 800mhz antenna and that helped some. I've read about using magnetic mobile antennas made for vehicles in the house or something like that? I really miss hearing my scanner.
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Old 10-24-2009, 2:48 PM
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Until I figure out whether I'm pulling up roots for greener pastures, I'm not to keen on climbing on the roof to install antennas and installing plates on the baseboard for coax connections. In the meantime, I use a seven element 800 MHz YAGI mounted to a stand that's used to support an elevated stage speaker. The speaker mast elevates to 80". The whole shebangh sits in front of a window that's facing the tower I want to hit. When I'm done listening, I break it down and store it in a closet. The improvement in reception is dramatic to say the least.

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Old 10-24-2009, 3:05 PM
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I will have to research that, thank you moga.
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Old 10-24-2009, 3:08 PM
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I know that you indicated you wouldn't know how to setup an antenna. However, if you know how to use a box wrench and can join two sections of wire by screwing the connectors together, you can set this rig up. It's as easy as pie and a good performer, at least from my second story window.

Good luck.
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Old 10-24-2009, 3:13 PM
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I was trying to find a model and I see you posted it.....geesh.....yes, I can do that. Hmm, not finding that model though.

Last edited by new_to_scanners; 10-24-2009 at 3:17 PM..
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Old 10-25-2009, 2:31 AM
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Yep I personally like the Yagi-Uda antenna and found that it can work wonders at least for stationary transmitters because there highly directional especially when you get one that has a large number of directors on it. So if you go with the Yagi-Uda antenna make sure you identify where the 800 MHz transmission tower you want to receive is at so you can point the antenna in that direction otherwise you will get subpar results.

As far as the window antenna goes I would recommend avoiding that at all cost since for starters when they designed that type of antenna they made assumptions about the thickness of the glass in an automobile which can be different than the thickness and type found in home window glass that will most likely result in impedance matching issue which may or may not be substantial since antenna theory is based on voodoo anyways. The real key point with the window mounting type of antenna is the fact that over time the weight of the antenna can damage and crack the house window glass especially if you live in an area that gets a lot of snow or has a lot of wind. I have seen this type of antenna mounted on a home window cause the window to crack in a nice semi circle across the window.

Magnetic mobile antennas are a middle of the road option if you want to listen to multiple 800 MHz systems that are located in different locations that the Yagi-Uda can’t cover because of physical location. Though I believe that particular type of antenna which is a monopole is limited in frequency range so if you want to scan more than just the near 800 MHz band you’re going to have problems but you will have similar problems with the Yagi-Uda in that regard as well and also you don’t get the large gain with the monopole as you do with the Yagi-Uda so if you’re trying to receive a far away station the monopole most likely won’t cut it.

In all truths antenna selection is one of those it depends on what you’re trying to scan and where what you’re trying to scan is located at. But I suppose you can’t go too wrong with a Yagi-Uda so give it a try and see what happens.
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Old 10-25-2009, 1:12 PM
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FleetAdmiral, thank you for taking the time to respond with all that information! I no longer believe the problem is weak reception, but rather interference. I actually was able to receive well until about a month ago, then something in my neighborhood must have changed and is interfering with the signal. On the opposite side of the house I can get better reception, not great, but better. I use to hear everything perfectly. So my question is, if the problem is not weak reception, but interference, would a yagi directional also work for that? I'm sorry to change scenarios on you, but last night I did a lot of trouble shooting and I can go 2 miles from my house and pick up everything. What could possibly have altered my reception.....
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Old 10-25-2009, 2:51 PM
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A cell tower could do it.

I have used a "powered" digital tv antenna from RS, and was able to improve my reception of a distant tower.

That powered antenna may not solve your problem if it is indeed interference, but it doesn't hurt to run to the Shack, try one and see. If it doesn't help, return it. They don't carry the one I have, and even though it isn't designed for 800 MHz, it sure seemed to work for me.


MM
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Old 10-25-2009, 3:59 PM
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That is a very interesting scenario,

And I believe the answer to that question would be it all depends on the type of interference you are experiencing.

For example in some odd twist of faith say a bird landed upon the transmission tower and bent the antenna (it was a really big bird) or someone improperly installed a new antenna on the tower causing modifications to the existing antenna pattern such that a null now exists in the direction of your house then no new antenna in the world would help solve this scenario.

Fortunately that scenario is unlikely since it would become obvious very quickly that service out in that region was severely diminished in a public service radio system so it would get fixed quickly.

A realistic scenario that could have occur is was there any large buildings created or destroyed in the last month that might have changed the signal strength between your house and the transmission source or maybe someone decided to reduce the strength of the transmitter’s output power at the tower.

If this is the case then the high gain from a Yagi-Uda antenna would work to compensate for a decrease in signal strength as a result of this case.

Another possible scenario is somebody or something is transmitting on or near the signal your trying to listen to or multipath is occurring off a large building or structure that is causing deconstructive interference at your particular location.

If this is the case then it all depends upon the direction that the interference is coming from in relation to the transmitter you are trying to receive. If the direction that the interference is coming from is not in the same direction as the transmitter then a Yagi-Uda high directivity would work as long as you pointed the Yagi-Uda in the direction of the transmitter. However if the interference is in the same direction as the transmitter then the Yagi-Uda would amplify both the noise and the signal you wanted to receive which depending upon the strength of the interference may or may not be helpful.

Honestly for this scenario, I don’t believe anyone would get away with transmitting interference near a band on purpose like that very long so the interference you are experiencing has to either be a local phenomena in either some electronic device you or your neighbor recently bought that is transmitting interference near that band or multipath interference is occurring which is sort of odd since this is a relatively new thing that has occurred. I suppose a new cell phone tower like 911scanner suggested could cause some reception issues depending upon the frequency and power they are transmitting at and your relative proximity but it’s really hard to say either way.

I suppose this is where a spectrum analyzer would come in handy since you could physically see if you have signal reduction or interference from another transmission source. I know that some scanners like a BCD396XT has a crude spectrum analyzer on it but if you don’t have access to some type of spectrum analyzer figuring out exactly what type of interference you are dealing with can be somewhat tricky.

In all cases a Yagi-Uda is not a bad way to handle most of the cases but if it were me I think I would pull up the FCC website and get the GPS coordinates of the transmission tower and plot that with respect to my house on Google maps and see if anything glaringly obvious appears. I also think the FCC website supports a search by GPS coordinates so you could always enter the location of your house into the system and do a 2 mile radius search and see if anything pops up that might be problematic.
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Old 10-25-2009, 4:17 PM
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My brain hurts. I just thought I could buy a scanner, turn it on, and hear cool stuff.......didn't realize how involved it was! Although I guess until a month ago that was pretty much what I did. Ok, I'm going to do the GPS coordinate suggestion, however.....how do I know which site to receive from when there are so many? Just take the one closest to my house? This is what the website shows:

Simulcast A: Phoenix Police and Municipal Services
20 frequencies (unknown which 20 of 39 below) transmitting from 9 sites in Phoenix:
Site 1 (WPNW554): Downtown Phoenix, 200 West Washington.
Site 3 (WPWX741): SW Phoenix, Fire Sta34, 50 N. 51st Ave.
Site 4 (WPWT692): Maryvale, 4020 W. Glenrosa.
Site 5 (WPWR968): Squaw Peak Area, Phx PD Substation, 6208 N. 24th St.
Site 6 (WPXE694): North Mountain (North Central Phoenix), 10600 N 7th St.
Site 7 (WPWS651): Sky Harbor Airport area, T4, 3800 E Sky Harbor Blvd.
Site 8 (WPWY575): Conv Fire Ops: Far N. Desert Hills. 701 W Carefree Hwy.
Site 9 (WPWS758): North Phoenix, Adobe Mountain, 23060 N. 27th Avenue.
Site 26 (WPXE706): NE Phoenix, 15040 N. Tatum Blvd.

I'm also going to try and track down a spectrum analyzer, that would be interesting. Back to the drawing board. I just know I miss hearing all the action. Something strange is going on because one night I turned on the scanner and it was dead and it was working fine the night before. I look like an idiot walking around my house all contorted trying to get a signal.....I do know my neighbor nextdoor plays in a band and I hear him practicing in his garage.....could something he set up cause this?

I would like to throw this out there too in and effort to problem solve - right now I have the scanner turned on on Simulcast A and it will stop on the talkgroups I have programmed briefly, but no sound. Would that suggest weak signal or interference - that it receives it but can't seem to lock in to transmit the voice....?

Last edited by new_to_scanners; 10-25-2009 at 4:25 PM..
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Old 10-25-2009, 4:48 PM
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How about this test,

First of all when you tune your scanner to the control channel as a conventional FM frequency, as in without trunking on do you hear what I like to call the diesel engine sound of the data stream?

If you do does it sound loud?

if it does then it is most likely some type of scanner related issue like attenuation being toggled on the control channel by accident meaning that you have more than enough signal strength

If you do does it sound weak or hissing sounding?

If it does then its signal strength of the transmitter or interference meaning that you need a new antenna.

If you don’t hear anything at all then maybe the control channel has changed and you need to find the new control channel.
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Old 10-25-2009, 6:01 PM
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OK, I did as you suggested and what I will get is a loud intermittent static sound......I wish I could fly you out here from North Carolina lol!
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Old 10-25-2009, 7:41 PM
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Well,

If you’re getting pure static and no data sound it sounds like either the signal is extremely weak or the control channel has changed.

Since you said you went 2 miles away and the scanner started working again I’m going to assume that the signal is weak.

I’m also going to neglect the possibility of interference for the moment to simplify things.
According to Glendale Public Safety Trunking System, Glendale, Arizona - Scanner Frequencies on Glendale public safety it says the system is a Project 25 Standard system so I’m assuming since you went several miles away and the scanner started working again that you have a Project 25 Standard scanner.

The next thing you can try is to turn the squelch all the way down on the scanner and perform the same FM conventional frequency test on each of the Glendale public safety trunk frequencies listed above and see if you can pick up a control channel. It’s possible that they have more than one transmission site and by using an alternative control channel it might start working again.

At the very least you should be able to pick up fragments of the control channel which would indicate that a better gain antenna would improve the overall reception thus making the system work again.
If you end up hearing nothing but static across all the channels, then this would indicate another problem but let’s not get ahead of ourselves
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Old 10-25-2009, 8:22 PM
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You are amazing, I will try this tomorrow. Although I get the Glendale PD loud and clear, they are on a different system than Phoenix. It is Phoenix I can barely receive. They cover two counties including mine, so I would think the signal is strong. I know the control channels have not changed, I have confirmed that. I have a Uniden BCD396T. I'll be back with you tomorrow. Thank you again for helping me troubleshoot this.

You know what else I was thinking though probably totally unrelated - but the remote on my TV also keeps working off and on. No, it's not the batteries....lol...the VCR and cable box work perfectly, but for some reason the signal from the remote to the TV probably only works 50% of the time. What is the normal frequency range for a tv/remote? Just curious.
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Old 10-25-2009, 10:31 PM
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Well I suppose on the bright side at least if you are able to get Glendale then the scanner works. I have a BCD396XT so our scanners are sort of similar so I bet that manual tuning to a particular frequency is rather frustrating since you have to create a new system then a group and then a channel. If your device had the band scope feature you could tune to those frequencies a little bit easier but I don’t believe the 396T has that option.

Anyways,

Most TV remote controls use a modulated IR optical led that has a wavelength around 400 to 700 nm which is considerably higher than any transmission your scanner can receive. If the batteries aren’t low then I bet your remote has a case of what I like to call greasy contact syndrome in which a nice layer of grease gets between the touchpad and the rubber keys causing an intermittent connection. The only way to solve this problem is to take the remote apart and use a paper towel to soak up the grease and reassemble the remote.

Maybe they took a transmission tower in your area offline or something; I’ve seen some county wide systems take additional transmissions sites offline if they are not being used or if they can get by just running one site for the county they might do so in order to save money.
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Old 07-24-2012, 8:39 PM
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Ok, I have an Pro-106 scanner, and I want to be able to receive the Cities which are 40 miles away. Does anyone have any idea what antenna will help me to accomplish this? I also dont wanna go over $50 bucks, and would like to buy from Scanner Master.

Thanks
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Old 07-26-2012, 12:35 AM
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Take a UHF TV antenna, turn it on its side (90 degrees), point it at the tower. Be sure to use good low loss coax and keep the length as short as reasonably possible.
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Old 07-26-2012, 7:47 AM
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But im talking about 800 mhz
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Old 07-26-2012, 8:11 AM
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Default Easiest way to Boost 800 MHz reception

An outside antenna, with the lowest loss coax possible. Rule of thumb (but not absolute) higher priced, better antenna.

Coax to not use for 800 Mhz. RG-58, RG-8, RG-8x.

Here are some attenuation charts. You are looking for the lowest loss at the desired frequency. The issue that many forget is although you might have a killer antenna at 100 ft, you lose what might gained by lossy coax.

Ham Radio Coaxial Cable Power Handling and Loss Specifications - Velocity Factors of Feedlines
Coax Attenuation Chart
Coaxial Cable Attenuation Chart

Besides Scanner Master, also check out Grove Enterprises.
Home

I currently both use a Diamond Discone that covers 25-1200 MHz, & a Grove Scanner Beam; and have used the Scantenna from AntennaCraft in the past with acceptable results.

You might find that the cost of the better coax equals or exceeds the cost of the antenna. However that might be what is necesary in your situation.
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Old 07-26-2012, 12:08 PM
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Thanks for the information!
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