Re: [digitalradio] 70cm -2M-6M-10M fan dipole ?

[KH6TY]

Andy,

You first have to decide if you will use horizontal or vertical 
polarization - vertical polarization mostly for working the repeaters on 
2M and 70CM, or horizontal polarization for working SSB stations.

Omnidirectionality is easy with vertical polarization but much more 
difficult with horizontal polarization. If you will be working 
repeaters, you do not need much antenna gain, but for SSB, you need much 
more gain.

The other question is the feedline. What transceiver are you using? Does 
it have separate antenna outputs for 2M and 70 CM? For example, on the 
IC-706MKIIG, the 2M and 70 CM antenna outputs are combined, so you can 
use a diplexer to send the RF to the two antennas from a single 
feedline. The 6M output is combined with the HF output, so that requires 
a separate feedline. You probably want horizontal polarization for 6M, 
and an aluminum dipole would be self-supporting. If you use two at 90 
degrees and switch feedlines with a switch, you have omnidirectional 
coverage on 6M.

On 2m and 70 CM horizontal polarization, I use bi-directional skeleton 
slots for each band, which gives me enough gain for DX, mount two at 90 
degrees to each other and just switch feedlines for omnidirectional 
coverage.

If all you are interested in is working repeaters, then a dipole for 6M 
and commercial 5/8 wavelength verticals for FM on 2M and 70CM will work 
with one feedline if diplexers are available to split 6M and 2m/70CM. 
Again, much depends on the antenna outputs of the transceiver, whether 
you should use a single feedline or two feedlines.

73, Skip KH6TY



On 7/20/2010 8:58 PM, obrienaj wrote:


 I am planning another HF installation soon and may have a 33ft mast
 begging for some extra creative thing to hang off it . I do not do 70cm
 -2M-6M much and think I should , just to be able to get out when there
 are bands openings. Nothing with DX in mind, just something
 omni-directional would do (or ANY direction) I was thinking about a
 fan-type dipole , one feed line going to dipoles for 70cm - 2M - 6M and
 maybe 10M. Most likely not fully horizontal , more of a sloper. Any
 thoughts on something like this? Quite a wide range of frequencies.

 Andy K3UK

AW: [digitalradio] 70cm -2M-6M-10M fan dipole ?

[Siegfried Jackstien]

What about a multiband verticl fort he uppoer bands .. Stacked with some
gain like the x 510 or the x 6000

Omnidirectional . 2 or 3 bands . with some gain . can be used also for local
repeater or emergency work .

Just an idea

For 6 and 10 better use a small beam 

But you can start with a ladderline fed dipole for 6 and 10

Many antannas possible so I would sax . see what you have in your junk box
and garage . and then make something with that parts.

Greetz

Dg9bfc

Sigi

 

 

[digitalradio] 70cm -2M-6M-10M fan dipole ?

[obrienaj]

I am planning another HF installation soon and may have a 33ft mast begging for 
some extra creative thing to hang off it .  I do not do 70cm -2M-6M much and 
think I should , just to be able to get out when there are bands openings.  
Nothing with DX in mind, just something omni-directional would do (or ANY 
direction)   I was thinking about a fan-type dipole , one feed line going to 
dipoles for 70cm - 2M - 6M and maybe 10M.  Most likely not fully  horizontal , 
more of a sloper.  Any thoughts on something like this?  Quite a wide range of 
frequencies.  

Andy K3UK