UHF/VHF

[Redback]

I have a what appears too be a VHF antenna base, it has one of those small bayonet fittings at the end of the coax that connects to the back of a radio (I don't have the radio) the base has RFI on it, the antenna is a steel whip that has to be tuned, can i use this base for a UHF antenna in place of the steel whip:confused:

My antenna is permenently mounted, I can't interchange antennas.

Baz.

[waynep]

You SHOULD be able to use that same antenna base for both a UHF and VHF whip. You can buy a ready made UHF whip that will screw on, or you can just cut down the VHF whip to UHF length - you'll need a cutting chart or VSWR meter so you can tune it to the right length- it's about 6" but exact length will depend on a few factors. ( a few mm can make quite a difference to performance )
As for the connector - sounds like it is a BNC fitting. If your radio doesn't have that, you can buy adaptors that will change from one style to another. You'll get a bit of loss doing that but nothing you'd notice.
RFI is the name of the manufacturer - used a lot in commercial circles.

Your question was a bit unclear so hope that helps a bit !

[Redback]

Thanks Wayne, I have an SWR meter from my 27Mhz days, will this work for UHF.

Baz.

[JDNSW]

Thanks Wayne, I have an SWR meter from my 27Mhz days, will this work for UHF.

Baz.

Probably not! Most 27mHz swr meters are limited to about 30mHz - UHF is 400!


John

[Pedro_The_Swift]

PICS PICS PICS!


a bit slow these days Baz,,

cold down there in the 'warra?
:p

[Redback]

Probably not! Most 27mHz swr meters are limited to about 30mHz - UHF is 400!


John

Thanks John.


PICS PICS PICS!


a bit slow these days Baz,,

cold down there in the 'warra?
:p

Yes i know no pics, I'm just seeing if i can use it first.

It's pretty warm this morning at 14, earlier it was 7 though, the last few days have been a bit warmer than usual.
Might be different next weekend though, at Oberon:eek:

Baz.

[Pedro_The_Swift]

I always reckoned Sunny Corner was colder---

Brrrrrr!

[waynep]

Yes we need pics - not sure what you mean by "can't interchange antennas"
I'm a bit confused as to what you have there - RFI do make a lot of different models.
Maybe you need to go through the RFI VHF antennas on their website and see which one looks like yours
http://www.rfi.com.au/wireless/mobile-antennas/mobile-antennas.html
If you've got one of the ground independent type with the "MBC" bases, I suspect those bases are unique to each band because they have a transformer inside them - but I'm not sure - I can ask the techos at work or maybe phone RFI.

[JDNSW]

I always reckoned Sunny Corner was colder---

Brrrrrr!

If you are comparing Sunny Corner and Oberon, I don't think there is much to choose - both are in the running as the coldest inhabited places in Australia!

John

[Redback]

Yes we need pics - not sure what you mean by "can't interchange antennas"
I'm a bit confused as to what you have there - RFI do make a lot of different models.
Maybe you need to go through the RFI VHF antennas on their website and see which one looks like yours
Mobile Antennas | Wireless | RF Industries (http://www.rfi.com.au/wireless/mobile-antennas/mobile-antennas.html)
If you've got one of the ground independent type with the "MBC" bases, I suspect those bases are unique to each band because they have a transformer inside them - but I'm not sure - I can ask the techos at work or maybe phone RFI.

ATM I have a Mobile One 4.5g antenna and it doesnt remove from the base, so to change to a higher gain i need to replace the whole thing right back to the CB:(

This
http://www.mobileone.com.au/antfrontp.png

I've always liked the Mobile One antennas, they have always been very good, especially 27Mhz

[waynep]

OOOOOkaaaaay... now i'm thoroughly confused ( or is it just me ) ... I thought you said you had RFI antenna ?

[Redback]

I have a what appears too be a VHF antenna base, it has one of those small bayonet fittings at the end of the coax that connects to the back of a radio (I don't have the radio) the base has RFI on it, the antenna is a steel whip that has to be tuned, can i use this base for a UHF antenna in place of the steel whip:confused:

My antenna is permanently mounted, I can't interchange antennas.

Baz.


OOOOOkaaaaay... now i'm thoroughly confused ( or is it just me ) ... I thought you said you had RFI antenna ?

The RFI base is the one i was hoping i could use to replace of my currant antenna and buy a UHF antenna that will attach to the RFI base it's an extra antenna that i was given.

Which allows me to change antennas when in different location (ie) low gain for hilly country or high gain for flat open country.

Baz

[rover4life]

best thing to do would be buy your self an elevatedd feed and be done with it havnt had any trouble using these in hilly country although you could just carry around a 2 db antenna and interchange if need be
Shaun