A99 becomes a Quad Bander...

[mr_fx]

well I finished it finally

a while back I gutted an A99 in order to convert it to a 20m vertical... never really finished it http://www.worldwidedx.com/amateur-...-converting-99-1-4-wave-20m-ground-plane.html

now the original radiator serves as a 20m 1/4 wave, and I have added a few other elements to make it into a 20m/15/10/6m verical

the process was simple, open up the bottom of the antenna and remove the matching section, replace it with a wire...

then drill a hole and attach the other elements, then attach some NONconducive standoffs to the a99 and you are pretty much done...

another option might be to make a jumper that connects before and after the matching section... this MIGHT allow you to run the A99 as a 20m 1/4 wave /10m 1/2 wave antenna, but it also might not work at all


Here it is. 20/15/10/6m. Made from
an old 1/2 wave cb antenna, some plastic clothes hangers, and some left over
speaker wire

 

[mr_fx]

another picture, got it on the test pipe... (water pipe)

So far the results are promising, BUT I will not have a really idea until I get it up on the roof and add the radials, 4 for each band (1/4 wave + 5%)

SWR readings so far:

20m leg

12.40 = 1.4:1
12.90 = 1.2
13.50 = 1.7
14.00 = 2.5
14.20 = 2.95
14.35 = 3.1


15m leg

20.20 = 1.1:1
20.50 = 1.15
21.00 = 1.75
21.20 = 1.95
21.45 = 2.5


10m leg

26.00 = 1.0:1
26.50 = 1.25
27.00 = 2.4
27.50 = 3.2
28.00 = 4.0
28.50 = 4.0
29.00 = 4.0


6m leg

44.95 = 1.05:1
45.50 = 1.45
46.00 = 1.8
47.00 = 1.7
48.00 = 1.6
49.00 = 2.2
50.00 = 2.2
51.00 = 2.0
52.00 = 1.7
53.00 = 1.7
54.00 = 1.7

Interesting readings on the 6m area... my guess is that it is a harmonic off the 20m leg... I notice in my mobile IF I forget to switch from my 20m antenna to my 6m, antenna that the SWR is quite tolerable, this MIGHT be the same deal here...

 

[The Mad Scientist]

very interesting.

 

[Moleculo]

You get extra points for creativity Have you had a chance to try it out yet? I know a few people that have made these types of antennas from scratch and have a whole lot of fun with them.

 

[mr_fx]

no real tests yet, but it receives really well, similar to my 102 whip on 10m, not quite as broad banded, once it is on the roof and has a proper ground plane o work against it should work just fine

 

[KG0MN]

very clever idea. It reminds me of the new vertical that Step IR is selling.

 

[Robb]

If you were to hang four radials fanned below it, it might work as a multiband center fed vertical dipole. However, it may not work out that way. In which case it still reminds me of the GAP Titan DX . . .

 

[vkrules]

Great idea, bet it was a bitch to tune!Whats going on at 10 meters ? Is that an unmatched 1/2 wave.

 

[mr_fx]

Great idea, bet it was a bitch to tune!Whats going on at 10 meters ? Is that an unmatched 1/2 wave.

not tuned yet, should not be any worse than any other fan type antenna

on 10m it is a straight 1/4 wave around 102"