Exterior antenna for 396T?

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mully95

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I have tried the "search" and just couldn't find the answer to my questions. So hopefully you can help me out please.

The Dilemma

I want to listen to the Anderson City PD but they transmit off P25 and it does not come in good where I live.

Palmetto (Project 25) Trunking System, , South Carolina - Scanner Frequencies

If I stand outside I do get some of their traffic but once inside I might as well say that I don't hear traffic from them at all. The scanner has a 800mhz duck on it at the moment. Now if I'm in the city limits it does better. Their tower is located at the Anderson University and when I'm close to it (within 100 yds) all signal bars are at max and reception is wonderful!! So I that eliminates any errors in my programing of the 396 from my understanding. I have read on here that all of the police agencies are slowly go to go over to the P25 in my area. The EMS has just converted over to the P25 on 2/11/2010 but they are still having traffic on the Pallmetto 800 as well as CVN. It seems they are heading in that direction.

Questions

1. I want to install a exterior antenna 20' to 25' above the ground and use Welcome To Times Microwave cable. What antenna do you suggest I use?

2. Would my 396T be damaged using a exterior antenna?

3. Or is the base models better suited for antennas of this nature?

4. The sheriff in my area operates on
System Type:Motorola Type II SmartZone
System Voice: Analog and APCO-25 Common Air Interface

I would hope the antenna would also help with this system as well. Would it indeed do that?
 

pwscott

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You won't damage the system. Scanner Master and Grove have lots of antennas for this. I like a discone antenna mounted in an attic for this myself.
 

mully95

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You won't damage the system. Scanner Master and Grove have lots of antennas for this. I like a discone antenna mounted in an attic for this myself.
Thanks. I'm learning and all the info I can get is appreciated.

So a antenna in the attic is as good as one outside without any structure around it? I have a total of around 6' in the attic and that is about it. I know if I take the scanner outside the walls of my house or sit it front of a window it does better. However with the P25 system (Anderson City) I barely pick it up at all even when I'm outside.
 

ka3jjz

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No outside away from anything that could cause reflections or shielding is always better. Height is important too. On 800, though, keep in mind that anything beyond 20-25 miles, depending on terrain and many other factors, is stretching the limits. If 800 is all you are interested in, you're likely to be better served with a small 800 mhz yagi pointed in the general direction of what you wish to hear.

A discone is an omni antenna - that is, it receives (more or less) equally well in all directions, on all frequencies it covers. There are other designs that also might deserve a little investigation, such as the DPD Productions Omni-X, or perhaps their wide band Yagi. The NilJon line of antennas (now marketed under MP Antennas is another possibility, although to be fair, there have been as many negative comments as positive ones about this line. Even PAR electronics has an antenna that was favorably reviewed in MT some years ago.

In other words, the advice is simple - do some research before you plunk your green down. Don't skimp on the coax, either - at 800, picking the right one will minimize your losses. Our Scanner Antennas wiki has links for these companies and many more (note that anything in blue is a link)

Scanner Antennas - The RadioReference Wiki

73 Mike
 

mully95

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KE5MC

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The attenuation specification for 400 and 600 will tell you which is better at the higher frequencies. The lower the better.

You might do better on purchasing and assembling the cable yourself, but lacking the tools or experience a pre-made cable might be the better choice. One item I would add is a short jumper cable from the end of the pre-made cable to the radio. 400 is stiff so where the cable ends the radio comes off the end inline with the cable run. Which for viewing or operations is not easy. Something like a Pomona 3 foot cable of RG58 with the correct ends would be OK. Usually that type of cable has BNC on each end so the mate to the antenna cable connector will need an adaptor. Yes, you will have some insertion loss, but the ware and tear on the radio antenna connector will make up for the slight loss.

The height and gain of the antenna by it's directivity will help with the long range reception. I can't tell from your post if there are closer systems you want to listen too. If they are close enough then you might hear them off axis of the main lobe of the antenna or not.

The question you asked about what will work to improve the reception is about gain and loss in the various parts of the system. At the hobby level we try the best we can afford and see what happens. A commercial enterprise will do a performance survey using the necessary equipment to measure signal strength and then calculate the various losses and gains. Then they can still have issues that have to be addressed.

You have a feel for how your radio performs with the 800 antenna. Take it up in the attic see what you get and compare it to the other locations. That will give you an idea what the height will do for you. You can try the DP antenna with a short cable in the attic too and see what you get. What happens with the addition of the long cable from the antenna location to the shack?. The cable specification will tell you the attenuation factor, but you don't know the starting point (radio & antenna in the attic) to clearly understand have much it will degrade reception in the finial configuration.

Good Luck, let use know the finial configuration and how it is working for you. We will learn from your setup and experience.


I don't want to skimp on the coax so will the LMR400 do the job? Or is LMR600 better?

Since I'm a novice what connectors am I going to need to connect it to the 396T?

I'm thinking this all I need. LMR-400 Coax Cable, 50', N Male & BNC Male
 

mully95

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The attenuation specification for 400 and 600 will tell you which is better at the higher frequencies. The lower the better.

You might do better on purchasing and assembling the cable yourself, but lacking the tools or experience a pre-made cable might be the better choice. One item I would add is a short jumper cable from the end of the pre-made cable to the radio. 400 is stiff so where the cable ends the radio comes off the end inline with the cable run. Which for viewing or operations is not easy. Something like a Pomona 3 foot cable of RG58 with the correct ends would be OK. Usually that type of cable has BNC on each end so the mate to the antenna cable connector will need an adaptor. Yes, you will have some insertion loss, but the ware and tear on the radio antenna connector will make up for the slight loss.

The height and gain of the antenna by it's directivity will help with the long range reception. I can't tell from your post if there are closer systems you want to listen too. If they are close enough then you might hear them off axis of the main lobe of the antenna or not.

The question you asked about what will work to improve the reception is about gain and loss in the various parts of the system. At the hobby level we try the best we can afford and see what happens. A commercial enterprise will do a performance survey using the necessary equipment to measure signal strength and then calculate the various losses and gains. Then they can still have issues that have to be addressed.

You have a feel for how your radio performs with the 800 antenna. Take it up in the attic see what you get and compare it to the other locations. That will give you an idea what the height will do for you. You can try the DP antenna with a short cable in the attic too and see what you get. What happens with the addition of the long cable from the antenna location to the shack?. The cable specification will tell you the attenuation factor, but you don't know the starting point (radio & antenna in the attic) to clearly understand have much it will degrade reception in the finial configuration.

Good Luck, let use know the finial configuration and how it is working for you. We will learn from your setup and experience.
When you was discussing radio performance with the 800 antenna..... I can pick up some of the traffic of the Anderson City here at the house but it really lacks. So I'm guessing that adding any type 800 mhz antenna would help greatly. I'm about 9 or 10 miles from the tower so I'm guessing the hilly terrain,tress, and the house walls is what killing my reception.

Ok check me out here please. I am going to start from my scanner then go towards antenna.

Scanner

Flexible coax = Pomona 2249-C-36 > Standard BNC Male-to-Male Coaxial Cable Assembly, 50 Ohm RG58C/U, 36 in. 2249-C-36 Pomona Test Equipment

Adapter = BNC(F)/1/BNC(F) 1 hole mount

50' of LMR 400 coax = LMR-400 Coax Cable, 50', N Male & BNC Male (They don't have pre-made cable in the LMR 600)

Antenna = DPD Productions - Scanner / Radio Antennas for Commercial & Hobbyist Applications

Will this work together?
 

K7CAR

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What you've posted is way over kill IMHO. If money is no object then go for it, but I bet you could get by with far less. I'm running the Antenna Craft ST-2 TV Antennas & Supplies - AntennaCraft  - Shop at SolidSignal.com - Page 1 at 35 ft. and getting signals out to 75 miles. If you're only 10 miles from the tower then you don't need a LP or heavy duty coax. Nothing wrong with that, get the best antenna, coax that you can afford and put it up as high in the open as you can, but for $30 if it works I saved you $175 and you have a multi band antenna that will serve you throughout the scanning range.

I'd try it out in the attic first. If it works there fine. Save yourself climbing on the roof and future weather problems. If not then take it up on the roof and get it up in the air. It's light enough that it won't be a problem mounting on a lightweight mast. You'll get 50 ft. of coax, so get the antenna out in the open away from any wires or metal. Try it in different locations you might be surprised at how much better one works over the other. The usual rubby ducky on most radios suck, so any form of outside antenna will be a huge improvement.
 

mully95

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What you've posted is way over kill IMHO. If money is no object then go for it, but I bet you could get by with far less. I'm running the Antenna Craft ST-2 TV Antennas & Supplies -*AntennaCraft* - Shop at SolidSignal.com - Page 1 at 35 ft. and getting signals out to 75 miles. If you're only 10 miles from the tower then you don't need a LP or heavy duty coax. Nothing wrong with that, get the best antenna, coax that you can afford and put it up as high in the open as you can, but for $30 if it works I saved you $175 and you have a multi band antenna that will serve you throughout the scanning range.

I'd try it out in the attic first. If it works there fine. Save yourself climbing on the roof and future weather problems. If not then take it up on the roof and get it up in the air. It's light enough that it won't be a problem mounting on a lightweight mast. You'll get 50 ft. of coax, so get the antenna out in the open away from any wires or metal. Try it in different locations you might be surprised at how much better one works over the other. The usual rubby ducky on most radios suck, so any form of outside antenna will be a huge improvement.
Well I have already placed the order for everything so it's a done deal now. I am so sick and tired of not receiving my favorite police site which is Anderson City. Back years ago when they was CVN it was a enjoyment to listen to it as well as the sheriff because they was on CVN also. However everyone has switched to 800mhz (digital) around here and the reception sucks! I don't know how many times I have heard the sheriff dispatcher say "10-9 your radio breaking up!". I think the system they use suck so I need all the antenna I can get. The EMS and Fire have a few left but they also have 800mhz digital also. EMS has just switched to P25 CAI and Fire has done the same.

Anyways I hope to get better reception. It's so bad that I don't mind shelling out a few coins to get better reception.
 

KE5MC

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mully,

Yes to your list of items in post #8 they should work together. I would call it the premium package.

Experiment with the radio and antenna in close proximity. The objective is to change the direction the antenna is pointing and observe the signal strength / audio quality changes. The best direction might not be the bearing directly to the transmitter. Plus, if there are more than just the one system you want to monitor there might be a good compromise direction you want to use.
 

mully95

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Anderson SC
mully,

Yes to your list of items in post #8 they should work together. I would call it the premium package.

Experiment with the radio and antenna in close proximity. The objective is to change the direction the antenna is pointing and observe the signal strength / audio quality changes. The best direction might not be the bearing directly to the transmitter. Plus, if there are more than just the one system you want to monitor there might be a good compromise direction you want to use.
Alright... thanks for the helpful information! I will use that when I set it up.

Should start receiving my items pretty soon. I'll let you know how it turns out. I really don't want to get my hopes up because I don't think the reception will ever be perfect no matter what I do.
 

mully95

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OK.... for anyone that is interested the scanner does much better with the antenna so far by my 2 hrs of listening. The P25(Anderson City PD/EMS) is amazing clearer than I thought it would be. The Motorola II/Smartzone (Anderson Sheriff) is better also but it wasn't that bad anyways. The Low band is same as always.

I noticed that if I bottom out the squelch to "0" that it digital does much better.... but I have to bump it up to "2" to keep it open.

I took my DirectTV dish down that is not in use any longer and slide the antenna pole down in it. I will guess that the antenna is at least 20 ft from the ground. This is only temporary until my mounting brackets arrive.

I will report back later on the reception but I can tell the scanner is not blocked by the house walls now.
 

KE5MC

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Excellent!

When reception improves to the point were the error in the data decreases the audio will get noticeably better.

Not sure what to make of the squelch comment. It was my understanding that for trunked systems squelch was not a player like it is for conventional. There are a few digital settings to play with that might improve your decoding. I don't recall where in the menus they are. Only one digital system I would call close and they come in well enough when I listen to them which is not often.

Good to hear the improvements exceeded your expectation. I know you had some $$$ invested in your antenna. In ham radio circles it is said that your 'shack' is only as good as your antenna.



...
The P25(Anderson City PD/EMS) is amazing clearer than I thought it would be. The Motorola II/Smartzone (Anderson Sheriff) is better also but it wasn't that bad anyways.

I noticed that if I bottom out the squelch to "0" that it digital does much better.... but I have to bump it up to "2" to keep it open. ...
 
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mully95

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Anderson SC
now u gotta research some sites that are 50+ miles away and see what else you can hear
I'm just glad I'm getting my home town better but I will see what I can do later on.


When reception improves to the point were the error in the data decreases the audio will get noticeably better.

Not sure what to make of the squelch comment. It was my understanding that for trunked systems squelch was not a player like it is for conventional. There are a few digital settings to play with that might improve your decoding. I don't recall where in the menus they are. Only one digital system I would call close and they come in well enough when I listen to them which is not often.

Good to hear the improvements exceeded your expectation. I know you had some $$$ invested in your antenna. In ham radio circles it is said that your 'shack' is only as good as your antenna.
The error rate is down to "3" at times so it is much better.

On the P25 (Anderson City) only if the dispatcher/officer is talking I turn the squelch up and the traffic will slowly go silent.... turn it back down it the traffic will come back. Just tried it again to see if I'm loosing my mind but it does go out when the squelch goes up.

The digital settings you're talking about is it the Digital AGC, Analog AGC, and gain? If so I was told by UPman that it didn't have anything to do with reception.
 

UPMan

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If squelch is set too high, the scanner will not open the audio path unless it gets a very strong signal. This is true even for trunked systems. Audio path is primarily controlled by signalling for trunked and conventionals that have CTCSS/DCS/NAC, but the signal always must "break squelch" in addition to any other control factor.
 
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