Things I have made for my FT-817
these are a few of the things I have done since getting back on air
first is a 80m - 2m portable vertical antenna , I modelled mine on PA0FBK's excellent portable whip antenna (see his site in the links page) basically all I did was use 20mm plastic electrical conduit for the former (didn't have a fishing pole 18mm in diam handy) which can be got from many DIY shops here in the UK.
first thing I did was count how many turn's per inch the wire took up ,used single stranded insulated wire (single core 1/0.6mm copper 22awg bell wire from maplins) result about 20 turns per inch
next I figured 360 turns = 18" so cut plastic pipe 22" long .
after that I marked (measured the taps as on PA0FBK's site) took off the extra few that was left over @ the end .
then removed insulation from tap points lifted the wire up in a small arch , twisted a small length of wire onto the arched wire .Soldered wire in place and hey presto this was my tap points .I decided using the little 2mm connectors frank used was a bit like hard work , so mr croc clip (2 of) and a length of wire is what I'm using for the connections.
then wrapped it all up in insulating tape (didn't have any heatshrink wide enough at hand).
only trouble I had with vswr was on 20m but I discovered it was the length of the connecting tap wire , once I figured this out , I twisted the extra wire back on itself , problem sorted.
this antenna really does work better with a counterpoise as Franks suggests eg on 80 I was getting a vswr reading of 2:1 on 1 frequency move a few hertz about or below and it skyrocketed.
with a 16m counterpoise I get vswr 1:1 with bandwidth of 40khz reaching 2:1 at the edges.
Don't expect miracles from this antenna its several S point down from a dipole on whichever band its set-up for , but it is ONE antenna which lets you get on air very easily.
The other thing I did was mount a BNC socket onto a sheet of metal (which I screwed onto some MDF)(well truth be told it was the case of an old CB radio) as a base , so counterpoise wire's connect onto that . This allows me to mount antenna away from the radio with a short length of coax, can also mount other antenna's onto base (its is a BNC connector after all). which allows quick comparisons of antenna's.
A very important thing I made for the FT-817 was a fuseholder and reverse polarity mod for the power leads (yaesu for some unknown reason decided the FT-817 power leads didn't need a fuseholder).
this was made from a 5 amp electrical extension cord joiner/extender box (got from DIY store). All that was needed was to remove some of the plastic internal wall's (handy if you got a mini drill or small grinding stone for a drill), fit fuseholder inside and solder/connect a diode across the + and - connections .
simple fix for a MAJOR omission from yaesu.
the other recent thing was a need for an ATU so I happened to have a old QRP ATU I had built many years ago. this did work but not good enough so after changing the coil and then changing it from a pi match to a T match (think I got it the correct way around ) it works a treat.
I am hoping to make a Z match ATU at some point ,for using long wires etc .