Portable antenne for FT817



I bought myself a nice little FT817 for the field and gardenwork. MFJ and other companies sell nice antenna`s using telescopic antennas with base coil underneath it.
But why buy this thing if you can make it yourself for lesser money. They cost about 90 euro`s or more here,  I can do that much cheaper.




Hey, a antenna like this is nothing else then a telescopic whip with a base loaded coil. You can buy these whips on HAM-fest for cheap. Mine has a length of 3 meters, now I have to wind my coil for it.  →






Things needed": 32x500mm PVC tubing, cover to close tube, pieces of brass 25x4mm, few M4 brass bolts, copper wire 0,75mm enamelled, banana plugs, duct-tape, RG58, PL-plug and a whip (MFJ 1954) ↓

Within the tube cover I made the brass threat to screw the whip into,..made 2 pieces of round bras,..5mm thick with a hole in it,  threated it with the same threat as the whip. and put them on both sides of the PVC cover. ↓



Test setup

I took the 32mm diameter PVC tubing, wound some 120 windings on it with the 0,75mm wire and soldered some taps on it. Soldered the top of the coil onto the brass cover at the base of the whip. And the coax onto the beginning of the coil. put on a 5mtr groudplanewire and connected my antenna analyser to it.
I measured for every band the SWR and put in into a spreadsheet so I could see how many windings I had at what frequency with the whip fully out.  →


So now I re-wound my tube with the seperate coil parts for every band, analyser on it again to check,..and all was OK per band with fully erected whip.

I took the FT817 and connected it,..on 20meters and called for a CQ,..on 4watts my first was HB2008EM,...only testing it and my signal was 59.

First QSO on 20 with HB2008EM


At the "Jutberg" (hamfest) I bought some banana-plugs to make the taps and finished the antenna the day after I went to the Jutberg. Connected the ground plane wire, 16m for 80m, 8mtrs for 40, 4mtrs for 20. One long wire with connectors for every band I will use. Now the SWR was crapp as hell,..don`t know why,..I had to shorten the whip by 2 sigments at evry band,...crap, so I had re-wire my coils. I did this and connected the analyser again,...everything OK again with fully extended whip. All band now 10-80mtrs are below 1:1.3 now.

I tried the antenna with the FT817 in June 2008 in Afghanistan, receiving was perfect, I heard some stations from Europe, Russia and Africa and I also worked them in SSB. I used a laptop power supply and internal batteries. Ground there was very dry (Khandahar region), Best reception was at eve or night. Next step is perhaps a even longer whip with a length of 4meters, but I have to build a new coil for that one.

And I will try to be QRV with digital modus,  so I have to buy a small laptop for it.

(AN-29-C telescoop,..NSN 5985-00-295-9160)


March 2009 I was in T6 again, with a laptop in digital modus. I worked some station in Africa and Russia. At the way home I visited Crete, so I was QRV there also from the beach . I worked some stations from my home region (PA7PYR and PD3AFO), my signal a 59 in the netherlands with only 4watts on USB in voice. Not bad.

QRV from T6

Antenna setup in T6


QRV at the beach from SV9

In the meantime I modified/upgraded my FT817. Inside I put a DSP filter I ordered from BHI from the UK. The original microphone has been modified too, and now incorporates a HF clipper with "Heil HC4" micro element, the socalled DX-dream machine. The clipper circuit board I bought from DF4SZ. The board can my build into the HM31 microphone case by taking out the OEM mikro and install the board wich is equipped with a electred microphone. This microphone can be taken out and a aftermarket HC4 element can be put in it`s place. But an extra transistor on the board needs to be soldered in to get an extra amplifier for this HC4 element. With these upgrades the FT817 has become more user friendly making QSO`s. With the DSP put in the average setting you can now hear stations wich are normaly covered with noise and hard to hear. Same for the clipper mike switched on or off, on 20meters testing it with a station from Crete (SV9) the audio is much better and sharper with the clipper switched on. Both are a very big improvement.


PVCpipe/PVC cover/brass parts  4 euro
3mtr telescop antenna 30 euro (van MFJ)
banana contra connector  7x 1,75
Piece RG58 + PL plug used