Indoor Public Safety UHF Antenna

Status
Not open for further replies.

WQOC472

Member
Joined
May 4, 2010
Messages
266
Location
USA
Hello, i was wondering if anyone had any info on a INDOOR UHF Antenna? I'm not allowed to have any outoor antennas on my apartment and i am in need of an Indoor antenna for my Kenwood UHF TK-840 Mobile Radio.
 

Alliance01TX

Member
Premium Subscriber
Joined
May 11, 2007
Messages
297
Location
DFW Texas
UHF Radio - Inside Antenna

Howdy

The 2-way radio you list is clearly not designed for 'indoor use' and without a proper ground plane, mounting, coax-connectors and proper grounding.....you are putting the radio at a high-risk on damaging the Tx side, at minimum.

Also, the RF energy output from the radio is a health hazard if operated at medium or high power along with RF burns & 'feedback' to the unit itself could lead to damage to the radio. High Risk !

If you are using the radio for 'receive only' then almost any antenna cut for UHF frequencies should work and researching would give you serveral options. But note - Receive Only !

You can research "No Ground Plane Antenna's" at your own risk as an option, but really would-not recommend for any indoor use, and especially above 5 watts output at maximum and you still need mounting to ensure to reduce hazards..... and hope the radio does-not interfer with other applications people in the complex are using (TV, Radios....etc...) as FCC would not be impressed if you are operating in without a FCC License if using on Transmit mode....

Thx
 

gewecke

Completely Banned for the Greater Good
Banned
Joined
Jan 29, 2006
Messages
7,473
Location
Illinois
Howdy

The 2-way radio you list is clearly not designed for 'indoor use' and without a proper ground plane, mounting, coax-connectors and proper grounding.....you are putting the radio at a high-risk on damaging the Tx side, at minimum.

Also, the RF energy output from the radio is a health hazard if operated at medium or high power along with RF burns & 'feedback' to the unit itself could lead to damage to the radio. High Risk !

If you are using the radio for 'receive only' then almost any antenna cut for UHF frequencies should work and researching would give you serveral options. But note - Receive Only !

You can research "No Ground Plane Antenna's" at your own risk as an option, but really would-not recommend for any indoor use, and especially above 5 watts output at maximum and you still need mounting to ensure to reduce hazards..... and hope the radio does-not interfer with other applications people in the complex are using (TV, Radios....etc...) as FCC would not be impressed if you are operating in without a FCC License if using on Transmit mode....

Thx

If you read his post a bit more closely,you'll see that his user name is his GMRS call sign.
And you are a tad bit mistaken! It is possible with out any harm to the radio OR the operator, to transmit using a magnetic quarter wave uhf mobile antenna on a refrigerator,file cabinet,etc. The amount of rf transmitted, is no danger due to the fact that your brain or pituitary gland will probably not spend extreme amounts of time next to the antenna!
Also using the radio with a uhf mag mount inside the house will work quite well as long as the antenna is tuned properly! ;)
RFI is not usually a problem for cable tv or DTV installs either,at uhf frequencies.
n9zas
kbsv4461
 

n5ims

Member
Joined
Jul 25, 2004
Messages
3,838
Hello, i was wondering if anyone had any info on a INDOOR UHF Antenna? I'm not allowed to have any outoor antennas on my apartment and i am in need of an Indoor antenna for my Kenwood UHF TK-840 Mobile Radio.
Get a large (4 drawer legal sized would be best) steel filing cabinet and commercial UHF antenna on a mag mount. Place the file cabinet near a window and the mag mount antenna on the center of the file cabinet. For safety, move several feet away from it while transmitting (although you should be OK if you just don't touch the antenna while transmitting at GMRS power levels). Not the best solution, but workable.
 

Alliance01TX

Member
Premium Subscriber
Joined
May 11, 2007
Messages
297
Location
DFW Texas
Indoor Antenna

Howdy

The prior post is correct 'if' GMRS is what you are using the radio for only.

I went on the very-limited information provided and did not jump to the conclusion that this radio was being used specifically for GMRS as it was-not mentioned in the note....

As to the safety aspect, since we did not have more data (size of room / proximity to antenna, et al..) I chose to err on the 'safe-side' ,wondering if someone would use High Power (25 Watts) sitting a foot or two away from the antenna....or with children playing around near same, etc...

Finally, the post was related to the actual Radio as typically used prior....also as you will kindly note the Subject Matter was "Indoor Public Safety UHF Antenna"...so that lead me to the conclusion this 'might' be used for Public Safety use....

So problem solved...

Thx

Bill
 

Gadget

Member
Joined
Dec 19, 2002
Messages
7
Location
Norfolk, Va.
Believe it or not, I've actually had some luck with a good 1/4 wave glass mount UHF antenna mounted inconspicusly on an upstairs apartment window with good results. The fact that he's using a mobile in the house/ Apt. made me think about it. Of course that was some time ago, and I don't believe they were the double- or triple-pane windows you see today that might affect it. Of course the old "cantenna" has worked well also.
 

WQOC472

Member
Joined
May 4, 2010
Messages
266
Location
USA
Hey Guys, Thanks.. I didnt Mention i am a GMRS Operator.. However i have a few channels in the Public Safety Band i have on "recieve only" I use the Radio for Storm Chasing.. My plan is my partner will sit in my apartment on a Kenwood TK-805D with a Pyrmid Power supply and ill take the advise on the File Cabinet.. I have one sitting right by my computer desk. He sits and gives me radar info from the internet to me in my car with my Kenwood TK-880 and a mag mount NMO antenna on the roof of the car. Thanks for the help guys.
 

newsphotog

Member
Joined
Jul 29, 2008
Messages
885
Location
Des Moines, IA
Believe it or not, I've actually had some luck with a good 1/4 wave glass mount UHF antenna mounted inconspicusly on an upstairs apartment window with good results. The fact that he's using a mobile in the house/ Apt. made me think about it. Of course that was some time ago, and I don't believe they were the double- or triple-pane windows you see today that might affect it. Of course the old "cantenna" has worked well also.
I have a Larsen NR72BNMO mount on a mag mount that sits on a coffee can in the window sill of my first-floor apartment. It works well. I believe the window is plexiglass.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
I have a Larsen NR72BNMO mount on a mag mount that sits on a coffee can in the window sill of my first-floor apartment. It works well. I believe the window is plexiglass.
That's a great solution. I have a Radio Shack PRO-97 trunking scanner that works well with the supplied rubber duck, but I know can work better if I can rig up some kind of antenna in the window. I, too, live in a ground floor apartment and can't put up an outdoor antenna.

So the coffee can acts as the ground, or, in this case, the grounds. Do you experience a slight or significant improvement in reception?

Dave
KA6TJF
 

newsphotog

Member
Joined
Jul 29, 2008
Messages
885
Location
Des Moines, IA
That's a great solution. I have a Radio Shack PRO-97 trunking scanner that works well with the supplied rubber duck, but I know can work better if I can rig up some kind of antenna in the window. I, too, live in a ground floor apartment and can't put up an outdoor antenna.

So the coffee can acts as the ground, or, in this case, the grounds. Do you experience a slight or significant improvement in reception?

Dave
KA6TJF
A little bit, not much. I think what really helps with reception the most is the fact that it's in the window sill. Five feet further inside/away from the window it really really suffers, especially on VHF.
 

SCPD

QRT
Joined
Feb 24, 2001
Messages
0
Location
Virginia
A little bit, not much. I think what really helps with reception the most is the fact that it's in the window sill. Five feet further inside/away from the window it really really suffers, especially on VHF.
Thanks. I think I'll pick up one of those 20 buck Scanner Master mag mounts and give it a try. I've got nothing to lose since I can use the antenna on my car.

Dave
KA6TJF
 
Status
Not open for further replies.
Top