getting ready to build a Fan Dipole, not sure what bands I should cut it for

[Mudfoot]

Beg, borrow an analyzer is your best bet.

Or get a nice pair of comfortable tennis shoes.

 

[wavrider]

what about steal, I could plan a daring midday robbery of the local bank and use the funds to purchase one.

If you do that you will not be building any fan dipoles, but you may meet Bubba while you are locked up.

 

[mr_fx]

Or get a nice pair of comfortable tennis shoes.

as in up and down all around until you get it right

 

[mr_fx]

If you do that you will not be building any fan dipoles, but you may meet Bubba while you are locked up.

that and building license plates

 

[mr_fx]

so i am guessing that I am way off here... but would a 160m (1.8-2.0MHz) dipole work on 80m? I mean if you take the center of the band and multiply it by 2 you get a frequency slightly above the center of the band, but still within the band on 80m.

Am I on on target so far? Or am I missing something here?

 

[wavrider]

so i am guessing that I am way off here... but would a 160m (1.8-2.0MHz) dipole work on 80m? I mean if you take the center of the band and multiply it by 2 you get a frequency slightly above the center of the band, but still within the band on 80m.

Am I on on target so far? Or am I missing something here?

Will it work? Yes.

How good will it work is another question.

Think odd harmonics.

 

[mr_fx]

Will it work? Yes.

How good will it work is another question.

Think odd harmonics.

I see so even multiple = BAD news, an odd multiple = good to go

So then this might be a general guideline on what could be used.

160m 1.9 x 3 - 5.7 nothing useful there

80m 3.75 x 3 = 11.25,. nothing useful there

40m 7.15 x 3 = 21.45 = high end of 15m, should be fine with an internal tuner

20m 14.175 x 3 = 42.525, nothing useful there

17m 18.118 x 3 = 54.354 = might be able to use a tuner and use it on 'The Magic Band'

15m 21.225 x 3 = 63.675, nothing useful here

12m 24.94 x 3 = 74.82, nothing useful here

10m 28.25 x 3 = 84.75, nothing useful here

6m 52 x 3 = 156, seems too far off for use on 2m, maybe if it was tuned to the bottom of the 6m band? or even a little lower


at this point he antennas are getting pretty small


2m 146 x 3 = 438 = near center of band on 70cm

1.25m 223.5 x 3 = 670.5, nothing useful here

70cm 435 x 3 = 1305, a little above 23cm

I see no reason to look any further

I really don;t see the point in 17m

so I guess I would need a 160m, 80m, 40m (which would also cover 15m), 20m, 12m, and 10m

however at the moment 12m is not a HUGE concern of mine, nor is 15m (but it is a free bonus from 40m) 17m and 30 are not anything I am interested in at the moment either

So that leaves 160, 80, 40 (and 15), 20 and 10 but that is still 5 bands.

I could make it a little less tricky by getting rid of the 10m legs and running my 10m off of my 11m ground plane and/or the 2 element quad I have been thinking about building. That would get the antenna to a simpler 4 bands (plus 15m)

 

[mr_fx]

So does this look right? I figure I should make the legs oversized and trim down as needed. As for 10 meters I guess I could use this old A99 I have laying around


136’(160m) on each leg
________________________________I_________________________________
70' (80m)
_____________________________I__________________________
35'(40m)
_______________________I______________________
18' (20m)
____________________I__________________

 

[Robb]

If you are into 160m; so be it.
If you are a CW guy; then you would want to cut the dipole for the center freq of each CW band.
If you are a SSB/AM guy; then you will want to tune/cut the 80m dipole for the 75m portion - with a 1:1 balun using high-quality ferrites - just for a cool measure/precaution.

I would cut wires for 75m, 40m, 20m, and 17m for the fan dipole.
Use the link I already posted as a guideline for the fan dipole.

Then I would use your vertical A99 for 10m, 12m, and 15m and put 2 -1/4 wavelength radials for each of those bands mounted at the base of that antenna at a 45 degree downward slope. That will give you a pretty fair spread.
But that is what I would do . . .

 

[MitchellB]

A few weeks ago I made and put up a 40/20/10 fan dipole. Length was not a problem, but the spread hung down so far that I had to cut top wires (40M) off because I could not get it up in the air high enough to get under it. I just run a 20/10meter dual band dipole. 20 meters works great, but the 10 meter lower wire has a very narrow tuned band width for some reason.

 

[wavrider]

The KJ4IIF Multiband "FAN" Dipole for 160, 80 and 40 Meters

Here step by step instructions and also a harmonic chart as to what you can expect on harmonics.

You also have to take into consideration mutual coupling.

May surprise you what is actually use able on a big wire fan dipole.

So does this look right? I figure I should make the legs oversized and trim down as needed. As for 10 meters I guess I could use this old A99 I have laying around


136’(160m) on each leg
________________________________I_________________________________
70' (80m)
_____________________________I__________________________
35'(40m)
_______________________I______________________
18' (20m)
____________________I__________________

 

[mr_fx]

Then I would use your vertical A99 for 10m, 12m, and 15m and put 2 -1/4 wavelength radials for each of those bands mounted at the base of that antenna at a 45 degree downward slope. That will give you a pretty fair spread.
But that is what I would do . . .

neat idea, BUT wouldn;t the 15m band be covered by the 40m on the 3rd harmonic?

 

[Beetle]

neat idea, BUT wouldn;t the 15m band be covered by the 40m on the 3rd harmonic?

Depends on what 40 meter frequency you pick. 7050, way down in the CW end, would get you at 21150. 7100 would yield 21300. 7200 = way out of the band at 21600.

This is just on paper, however. With a short run of good quality coax and a good "tuner" (I wouldn't expect too many internal tuners to work all that well), you might get decent results.

With a good manual tuner, I'd just use a center-fed doublet as long and as high as I could reasonably get it, feed it with 450 or 600 ohm parallel line through a balun and get on the air.

 

[hookedon6]

...With a good manual tuner, I'd just use a center-fed doublet as long and as high as I could reasonably get it, feed it with 450 or 600 ohm parallel line through a balun and get on the air.

<More audio><More audio><More audio><More audio>

 

[mr_fx]

Then I would use your vertical A99 for 10m, 12m, and 15m and put 2 -1/4 wavelength radials for each of those bands mounted at the base of that antenna at a 45 degree downward slope. That will give you a pretty fair spread.
But that is what I would do . . .

Well I did this. I will try to get a picture later today.