Base Antenna for 700MHz Trunked

Status
Not open for further replies.

Deziel0495

PE/NB Database Guy
Database Admin
Joined
Feb 11, 2008
Messages
963
Location
PEI
I'm on the search for an antenna to improve my reception of the 700MHz trunked radio system in my area, the Maritime Public Safety Radio Network.

Ideally, I'd like to mount an antenna in my attic, the roof is shingles, not steel. From my house, I can currently get 3 sites (although 2 of them can be hit and miss) with just a cheap $20 mag mount wideband off Amazon setting on the desk beside the scanner.

I have 1 site in my town, just a few blocks over. I have 2 sites to my west at 18 km and 29 km respectively and 2 sites to my east at 22 km and 33 km respectively that I would like to monitor. There are more sites further east and even across the straight in New Brunswick but that's pushing almost 50 km.

These distances are measured in a straight line from my house right to the tower using google maps. Terrain should not be an issue, my province is basically flat, at least in my part of the county.

Any guidance and suggestions are welcome. I only plan to monitor 700, if anything else it would be VHF within my own town so very local.

I've been doing lots of research between discone and yagi and have been leaning more towards a yagi, pointed to the east as that's where I'm more concentrated on receiving. But then I've also been looking at using a 700MHz mobile antenna with a good ground plane. I'm no expert on antennas! :LOL:
 
Last edited:

Deziel0495

PE/NB Database Guy
Database Admin
Joined
Feb 11, 2008
Messages
963
Location
PEI

JimD56

KO9JAD/Fire Lieutenant/Paramedic
Feed Provider
Joined
Nov 18, 2004
Messages
818
Location
Davie, FL (Miami/Fort Lauderdale Metro)
I run a 700-800mhz Yagi in the attic pointed right at my closest simulcast antenna, about 6 miles away. RG6 Cable 20 foot drop into an Electroline LL2200 +15db amp then from there into an Electroline EDA2800 8 Port +7db amp in the rack. Antenna and Cable Amazon, Amps off of Ebay. Don't know about shipping to Canada.
 

bchappuie

Member
Joined
Dec 19, 2002
Messages
162
Location
Olathe, Kansas
A 5" piece of 1//8" steel rod soldered onto an SO-239, mounted on a 6" piece of steel flashing work pretty good with some elevation.
 

Deziel0495

PE/NB Database Guy
Database Admin
Joined
Feb 11, 2008
Messages
963
Location
PEI
So this is what I had in mind. I can't find a ground plane kit that does any higher than 512MHz, at least not on eBay.

Still open to suggestions and guidance. Won't be ordering anything until next week likely so that will give me plenty of time to research.
 

Attachments

  • Screenshot_20210406-122639_eBay.jpg
    Screenshot_20210406-122639_eBay.jpg
    44.6 KB · Views: 33

prcguy

Member
Premium Subscriber
Joined
Jun 30, 2006
Messages
16,312
Location
So Cal - Richardson, TX - Tewksbury, MA
Get the cheapest pit tin you can find and drill a hole in the center for a NMO to N or SMA adapter. Total cost probably less than $12. Here is one of many NMO to N adapters. N Female to NMO Mount Female Bulkhead Adapter BRACKE BM50648 | eBay

So this is what I had in mind. I can't find a ground plane kit that does any higher than 512MHz, at least not on eBay.

Still open to suggestions and guidance. Won't be ordering anything until next week likely so that will give me plenty of time to research.
 

CanesFan95

Analog already is interoperable.
Joined
Feb 14, 2008
Messages
3,235
Location
FL
I once went to a sheet metal place and ordered a few pieces of 2' x 2' sheet metal with 3/4" holes cut in the middle. Then I attached the NMO mount & antenna and used that for an attic install. Antenna Farm has an option to order custom-length coax on an NMO mount, and I'd recommend asking for LMR-240 instead of RG-58 or RG-8X, for lower signal loss. But sorry about this shipping prices! That really kills the deal.
 

Anderegg

Enter text in this field
Premium Subscriber
Joined
Mar 7, 2010
Messages
2,678
Location
San Diego
When I had weak signal of a distant 800MHz trunked system, before they upgraded and pointed the antennas in such a manner as to preclude any reception, I used a small cheap cell phone yagi. I litterally took a mag mount, put a NMO base on it with the whip removed, and used a long round shipping tube from The Antenna Farm slid over it to clamp the yagi too (it is light). I then rotated it around until it got max signal. The yagi was of the stamped out of sheet aluminaum style, so like 12 inches long, not heavy, and it gave better performance than any high gain NMO 800 antenna or handheld 800 antenna. The ability to rotate it and tilt it for max performance, and it's somewhat small footprint, really made it shine. The only troublesome part is mounting...I was fortunate enough to have a desk with a large subwooofer that I used as a stand next to my window. If you have one weak site, and several good sites, pointing at the weak site shouldn't kill your good signal sites assuming they are not also very weak signal. I tune by using the control channel as a conventional and moving and pointing until I get max -dBm on my scanner.

Paul
 

danesgs

Member
Joined
May 21, 2008
Messages
486
Location
Leesburg VA
JimD56,
Just curious, are you using it to transmit or just receive? And how did you tune it? service monitor?

Greg-KJ4DGE
 

JimD56

KO9JAD/Fire Lieutenant/Paramedic
Feed Provider
Joined
Nov 18, 2004
Messages
818
Location
Davie, FL (Miami/Fort Lauderdale Metro)
JimD56,
Just curious, are you using it to transmit or just receive? And how did you tune it? service monitor?

Greg-KJ4DGE
Receive ONLY. 700mhz Simulcast SDSS200 and 2-BCD996P2's covering 800mhz P25 Phase 2. It goes into a Comet Duplexer combined with VHF/UHF Diamond Discone then a single 20-foot RG6 cable drop into the shack.
 
Status
Not open for further replies.
Top