• 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.

Foldable Rubber Duck?

Status
Not open for further replies.

Seven-Delta-FortyOne

Member
Premium Subscriber
Joined
Apr 24, 2014
Messages
229
Location
The Emerald Triangle
I'm looking for an antenna like this, except in 460MHZ range.

MFJ Enterprises Inc.

Yes, I tried google, they don't seem to carry one.

What I'm trying to do, in case anyone has a better idea, is set up a very low power GMRS base station.

We use GMRS at the ranch, and the "base station" at this time is just a Kenwood TK-380. Works fine, except I am constantly charging the battery, and then is has to be taken out of service for 2 hours.

I have a couple TK-880H radios, with power supply and cabinet, and 5/8 wave base antenna. Works great, I just don't need to be transmitting daily ranch activities all over 3 counties, (I'm up on a hill).

The TK-880H will only turn down to 10 watts, so inside a house, with a rubber duck will be about perfect.

If I could use an inline attenuator, and put out about 1 watt ERP from the base station antenna, that would probably work as well. I don't know anything about reducing signals, however. I'm always doing the opposite.


Thanks for any help or suggestions.



Delta
 

mmckenna

I ♥ Ø
Joined
Jul 27, 2005
Messages
14,702
Location
SNCZCA01DS0
Running a rubber duck antenna off the back of a mobile will probably lead to high SWR, which may lead to improper operation of the radio. While I understand you want to reduce the coverage, you do want to keep things working properly.

Some options:
1/4 wave ground plane antenna. (easy to make yourself)
Small mag mount with a 1/4 wave
Small mag mount with a rubber duckie antenna
 

Seven-Delta-FortyOne

Member
Premium Subscriber
Joined
Apr 24, 2014
Messages
229
Location
The Emerald Triangle
Coaxial Adapter, BNC Female / UHF Male (PL259) - BA50

I'd get one of these and use a BNC 90 on the back of it and just use any old duck made for the correct frequency range. I don't know how well what you're describing is going to work but that's where I'd start.

That might work, but I'd have to get a PL-259 90 degree.



Running a rubber duck antenna off the back of a mobile will probably lead to high SWR, which may lead to improper operation of the radio. While I understand you want to reduce the coverage, you do want to keep things working properly.

Some options:
1/4 wave ground plane antenna. (easy to make yourself)
Small mag mount with a 1/4 wave
Small mag mount with a rubber duckie antenna

I didn't know that about the rubber ducks on a mobile.

I could go to a 1/4 wave, but I'd still be far over the power necessary. I can hit 3 repeaters in adjacent counties with a VHF handheld from my ranch. I also check into a VHF simplex net that covers about 4 counties from my place on my base station.

Since some transmissions can get a bit candid, not bad, just personal, I'd like to limit range as much as I can.


Delta
 

kayn1n32008

ØÆSØ
Joined
Sep 20, 2008
Messages
6,267
Location
Sector 001
That might work, but I'd have to get a PL-259 90 degree.






I didn't know that about the rubber ducks on a mobile.

I could go to a 1/4 wave, but I'd still be far over the power necessary. I can hit 3 repeaters in adjacent counties with a VHF handheld from my ranch. I also check into a VHF simplex net that covers about 4 counties from my place on my base station.

Since some transmissions can get a bit candid, not bad, just personal, I'd like to limit range as much as I can.


Delta


Most hand held antennas don't give a portable a 1:1SWR match. I know because I did a bunch of tests with some hand held antennas for Jerry at CSI.

If you want to really reduce range, take your mobile to a shop that has the correct software and test gear, and have them set the low power setting to 5 watts, then program your channels for low power.

A cheap and easy attenuator at GMRS frequencies, is about 10 metres of RG-58. At 460MHz, that should attenuate your 10w carrier by at least 3dB(5w out the other end) if you need less power, at another 10 metres. Use an NMO 1/4wave with a base station adaptor(0 gain) and you should be good to go.

This is the ONLY time is will say this about 400MHz feed lines: Skip the high quality coax, use something cheap and lossy like RG-58.

It is really lossy at 460MHz. No, you will not hear as well, but if you are using a portable from inside a building, you should be just fine.

UHF is more about LOS than power. I think you will find, if you are using an outside antenna, that even with a couple of watts into the feedline, you will still overshoot your ranch quite significantly. Especially if the office is on high ground.
 

pinballwiz86

Member
Premium Subscriber
Joined
Jan 15, 2013
Messages
1,489
Location
Missouri
Since some transmissions can get a bit candid, not bad, just personal, I'd like to limit range as much as I can.
Get yourself a dummy load instead of an antenna. Go ahead and google dummy load to find something you like and is rated for the 10 watt power level and length of your transmissions. Connect your equipment to a dummy load, and you will limit your range to just your property!
 

kayn1n32008

ØÆSØ
Joined
Sep 20, 2008
Messages
6,267
Location
Sector 001
I'm looking for an antenna like this, except in 460MHZ range.

MFJ Enterprises Inc.

Yes, I tried google, they don't seem to carry one.

Delta

Back in the day TopCon had a UHF rubber duck antenna that could be vertical or bent over on a hinge at 90 degrees they used for their Hiper head RTK rover. I think Larsen may sell a specialty antenna that does what you are looking for. Like mmkenna said, it is not a good idea though. Transmitting high power RF that close to both you and the radio is not a good idea.
 

Seven-Delta-FortyOne

Member
Premium Subscriber
Joined
Apr 24, 2014
Messages
229
Location
The Emerald Triangle
Most hand held antennas don't give a portable a 1:1SWR match. I know because I did a bunch of tests with some hand held antennas for Jerry at CSI.

If you want to really reduce range, take your mobile to a shop that has the correct software and test gear, and have them set the low power setting to 5 watts, then program your channels for low power.

A cheap and easy attenuator at GMRS frequencies, is about 10 metres of RG-58. At 460MHz, that should attenuate your 10w carrier by at least 3dB(5w out the other end) if you need less power, at another 10 metres. Use an NMO 1/4wave with a base station adaptor(0 gain) and you should be good to go.

This is the ONLY time is will say this about 400MHz feed lines: Skip the high quality coax, use something cheap and lossy like RG-58.

It is really lossy at 460MHz. No, you will not hear as well, but if you are using a portable from inside a building, you should be just fine.

UHF is more about LOS than power. I think you will find, if you are using an outside antenna, that even with a couple of watts into the feedline, you will still overshoot your ranch quite significantly. Especially if the office is on high ground.
Thank you to all who responded.

I'm rethinking this whole set-up now.

I really appreciate all the help I get here. It always amazes me the knowledge that you folks have, those of you who work in the industry.


Delta
 
Status
Not open for further replies.
Top