• To anyone looking to acquire commercial radio programming software:

    Please do not make requests for copies of radio programming software which is sold (or was sold) by the manufacturer for any monetary value. All requests will be deleted and a forum infraction issued. Making a request such as this is attempting to engage in software piracy and this forum cannot be involved or associated with this activity. The same goes for any private transaction via Private Message. Even if you attempt to engage in this activity in PM's we will still enforce the forum rules. Your PM's are not private and the administration has the right to read them if there's a hint to criminal activity.

    If you are having trouble legally obtaining software please state so. We do not want any hurt feelings when your vague post is mistaken for a free request. It is YOUR responsibility to properly word your request.

    To obtain Motorola software see the Sticky in the Motorola forum.

    The various other vendors often permit their dealers to sell the software online (i.e., Kenwood). Please use Google or some other search engine to find a dealer that sells the software. Typically each series or individual radio requires its own software package. Often the Kenwood software is less than $100 so don't be a cheapskate; just purchase it.

    For M/A Com/Harris/GE, etc: there are two software packages that program all current and past radios. One package is for conventional programming and the other for trunked programming. The trunked package is in upwards of $2,500. The conventional package is more reasonable though is still several hundred dollars. The benefit is you do not need multiple versions for each radio (unlike Motorola).

    This is a large and very visible forum. We cannot jeopardize the ability to provide the RadioReference services by allowing this activity to occur. Please respect this.

Indoor VHF Antenna

Status
Not open for further replies.

70cutlass442

Member
Joined
Jan 24, 2010
Messages
404
I am adding a VHF receiver to our high school for the police radio system. My original plan called for a Larid fiberglass antenna on the roof bu have some concerns that I will lose some sensitivity directly under the antenna inside the school. Would I be better off installing a RX antenna inside the school someone, say in the middle? Is there a good antenna to use? My current idea would be to take a ceiling tile and place a metal plate in it as a ground plane and use a Phantom or some other low profile antenna.

Has anyone done something similar that can offer some input?
 

mmckenna

I ♥ Ø
Joined
Jul 27, 2005
Messages
24,393
Location
I am a lineman for the county.
Not sure I understand.
Are you adding a voting receiver setup to assist with repeater coverage?

Location will depend on where your coverage deficiencies are. If indoor coverage is the issue, then an antenna indoors might help.
 

Ubbe

Member
Joined
Sep 8, 2006
Messages
9,285
Location
Stockholm, Sweden
If you use a non gain antenna it will have coverage under it and usually radiosignals will bounce around anyway and find it's way up to the roof. If you have a metal roof on the building then you probably have to make other arrangements. It all depends of the size and structure of the school and needs one guy with a radio connected to the antenna you plan to use and at that location and another guy running around doing radio tests. It should be done using a free adjacent frequency or TG.

In large buildings like a hospital with 4-5 different floors and a basement below ground level I used antennas, GP type that doesn't require external groundplane, at the center of each floor connected to a receiver and a RX voting system.

/Ubbe
 

N4DES

Retired 0598 Czar ÆS Ø
Joined
Dec 19, 2002
Messages
2,420
Location
South FL
The maximum amount of gain is on the horizontal plane, so if there is something adjacent to the building you can put the antenna on the better.
When I deployed a small downtown trunked system, that has a primary use is to provide in-building coverage in our 14+ story County Courthouse and nearby State Attorney/Public Defender building, I put it across the street on a top of an adjacent building.
 

Ubbe

Member
Joined
Sep 8, 2006
Messages
9,285
Location
Stockholm, Sweden
If you are allowed to put up an antenna at adjacent buildings you could use a high gain directional antenna pointing at the school.
But it all depends of how large the school building are. It's anyhow often most convenient and economical to install an antenna inside the same building.

/Ubbe
 

cmdrwill

Member
Joined
Mar 30, 2005
Messages
3,984
Location
So Cali
And Fred KNOWS what he is talking about.

So, we NEED more complete information on the existing system.
 

WB9YBM

Active Member
Joined
May 6, 2019
Messages
1,390
Just a side-note regarding fiberglass: I've seen deterioration caused by UV. The most common solution I've heard about is after cleaning it using metal-free paint for protection...
 

Ubbe

Member
Joined
Sep 8, 2006
Messages
9,285
Location
Stockholm, Sweden
Radiating coax are extremly expensive and you have to treat it as an antenna, using plastic standoffs to keep it at least 5 inches off any metal and the total cost incl installation are huge. You only see that being used in tunnels and locations under ground and anywhere where walls cannot be penetrated with RF signals.

Most buildings can use a single antenna to cover one floor. Installing the radio in a room next to the antenna will spare the cost for extended lenghts of expensive quality coax.

/Ubbe
 
Status
Not open for further replies.
Top