FAN DIPOLE FOR 80, 40, 20, AND 10 METER BANDS

I have two antenna, both dipoles.  One is a 20 meters with a 50 ohm RG-8u cable feedline. It works great from the top to bottom of the band. The other antenna is cut for 80 meters with a ladder line feedline. It is extremely narrow. Nevertheless, I can use it on 40 and 10 meters with my tuner. 

The problem is with the ladderline. The only way to feed it into the shack is to feed it through (or at least the easiest) is to pass it through the same holes that have an iron pipe and over the metal support of drop ceilings. I understand that this is not good. I am too poor to get more cable. The solution, use one feedline. Enter Google Search. There are a lot of interesting options out there.  

1. QSL.net has a lot of information on dipoles, including a Multiband Dipole with a single coax feedline. It does not have building details. What it does have is some key information. Interference between the dipoles is possible if the wires are too close together. 

2. Hamuniverse.com describes a multiband fan dipole with seems interesting. The quote a study by the Stanford Research Institute that says the at the connection point the dipole wires should be at least 5 1/2 inches apart and at the far end and least 38 inches . In a 3 dipole antenna, the figures would be:

• 75 meters: 0.96 time 468/MHz (for @3.85 this would be 121ft 6in total length)

• 40 meters (can be used on 15m as well): Exactly 468/MHz (for @7.20 this would be 65ft)

• 20 meters: 1.01 times 468/MHz (for @14.225 this would be 32ft 11in) 

I would like to include 10m as well so these numbers might need to be adjusted. 

• I can find only one discription of such a configuration built by VE2XIP. However, with my limited space, a already need to let the ends of the 80 meter antenna hang. The horizontal length is probably a half of the overall length. 

• I found another design at MOPZT.com that does not have the 80 meter antenna. What it does show is the 40 meter dipole folded back on itself making the over all length just a little longer that the 20 meter band. 

I will have to play around and combine some good ideas of each source. I will start by cutting lengths of wire to the following dimentions

75 Meters - 61.5ft x 2 (start with current antenna)
40 Meters - 33.5ft x 2
20 Meters - 17ft x 2 (start with current antenna)
10 Meters - 9ft x 2

Supplies:
1:1 balun
16 ft PVC or pacers