WiremanJPoles 
The CE0Y7mTripleLeg  The CPole  Vertical.L 
JPole antennas for 2m40m with Wiremancable (DK7ZB) (a JPole with 300OhmTwinlead for 145MHz see down) 

The picture shows the scheme of a JPole antenna. The high impedance feeding point of a lambda/2wire (L1) is matched from some KOhms to a low impedance with a lambda/4 matching sector (L2). The point XX has an impedance of 50 Ohm for direct feed with a coax cable. XX is symmetrical, a choke or balun could be useful to avoid sleeve waves on the screen of the coax. A very simple method for the lambda/4part is to use a 450OhmWireman cable. I have built up the antenna for 2 m, 6 m, 12 m and 30 m. The table gives the values for experimenting with the other bands. L1=0,471 lambda (HalfwaveRadiator) L2=0,223 lambda (Wiremancable) Solder the braid of the 50Ohmcoax at the right X, the inner conductor to the left X. XX about 510% of L2. 
The antenna can be mounted in several ways:
The classic JPole with both sections mounted vertically. Length 3/4lambda, only for the higher bands.

It is no difference in the radiating conditions, if the lambda/4part is vertical or horizontal. The pattern is identical with a vertical dipole. 
Both parts horizontally mounted 
The "Zepp"configuration 
The antennas were tested on 2 m, 6 m, 1 2m and 30 m. The lengths for the bands marked with "*" have not been tested, try with he given dimensions. For other frequencies use the following formula for insulated 2mmwires for L1. Notinsulated wires need a longer L1section. The points XX are 510% from the shorted part of the Wiremancable (look for best SWR). For the 50MHzJPole look on the special page: 50MHzHalfwaveVerticals 
Band 
l/2
Wire 
l/4
Wireman 
XX 
F_{o}
MHz 
SWR

Bandwidth 
40m* 
20,02 m 
9,46 m 
73,0 cm 
7,05 
 
100 KHz 
30m 
13,96 m 
6,61 m 
58,5 cm 
10,12 
1,1 
150 KHz 
20m* 
9,98 m 
4,73 m 
35,0 cm 
14,15 
 
200 KHz 
17m* 
7,80 m 
3,70 m 
26,5 cm 
18,1 
 
250 KHz 
15m* 
6,66 m 
3,15 m 
22,5 cm 
21,2 
 
300 KHz 
12m 
5,67 m 
2,67 m 
18,5 cm 
24,91 
1,0 
350 KHz 
10m* 
4,96 m 
2,45 m 
15,5 cm 
28,5 
 
500 KHz 
6m 
2,815 m 
1,33 m 
6,5 cm 
50,15 
1,1 
1000KHz 
2m 
97,5 cm 
47 cm 
3,5 cm 
145,2 
1,0 
1500 KHz 
The WiremanJPole during the DXpedition of Tom, DL2RUM as FS/DL2RUM

The result of 10 Minutes work with the 12mJPole, mounted on a fishing rod:
SWR > 1,3 21,121,3 MHz

The 50MHzJPole see: 
JPole with 300OhmTwinlead for 145MHz
The JPole for VHF and UHF constructed with 240Ohm or 300OhmTwinlead The lengths are for 145 MHz and 435 MHz. The 2mJPole can be used on 70cm, too with an SWR <1,6. SWR 145146 MHz <1,5 SWR 430440 MHz <1,6 The dimensions of A, B and C are in the table below Attention: The mounting in a plastic pipe or with tape on a fishing rod will detune the antenna to lower frequencies and needs a little bit of correction! 
Lengths for the bands 2m and 70cm
Band 
A 
B 
C 
145
MHz 
137cm 
42cm 
30mm 
435
MHz 
45,7cm 
14cm 
20mm 
The connection of the RG178 coax cable, here 240OhmTVwire
The same construction with 300Ohmwire. The cable is available at DXWire
The cut piece of wire between the parts A and B at the right side of the JPole
The 2mJPole ready for use At the top is a hole for a rope. The antenna can be mounted in a tree or any other support. 