The AM Forum

Howdy.  Im working on a Tuna. Does anyone have a source for insulated shaft couplers rods etc.  Looking for a supply house not fleabay

I checked the usual places without luck: Surplus Sales, Fair Radio, Radio Daze, AES in Mesa.
Plenty of fixed shaft couplings. 

Perhaps you could use two fixed couplings with a fiberglass or wooden shaft to insulate them!  bill

http://www.newark.com/omron-industrial-automation/e69c06b/coupling/dp/38B390
Omron makes an "Encoder coupler" in flexible resin that would insulate. However, it does not have an insulation rating.  Not important for signal level, but may not be suitable for High Voltage applications.  About $24.

https://www.mainline-group.com/collections/couplers-and-drive-hardware

FOUND IT!

Jackson Brothers in the UK makes many old radio parts.  You can order direct from Mainline or search for a US distributor.  Good luck!

Any materials supply house will have nylon, delrin, phenolic and other insulating 1/4 rod.
You need to cut to size. (online, mail order too...) Check hobby shops too...

They also sell brass, aluminum, steel and stainless rod.

For flexible couplers aside from epay where they doubtless exist, I have a trick.

I've used 0.250" ID rubber or vinyl tubing and an appropriate method to affix the tubing and
rod... the spring or crimp type hose clamps will do, as will the usual screw type hose clamps...
obviously this makes for a flexible shaft coupling. (don't select the black automotive tubing with steel
reinforcement, aka hydraulic tubing)

(filling the internal area will increase the breakdown voltage through the otherwise open airspace inside
the tubing)

An alternative is to get some lucite/acrylic/polycarbonate cylindrical (or other) shape of greater
diameter to the shafts you are trying to couple, then drill to accept the shafts, add tapped
holes from the perimeter to hold the shafts...  phenolic will work nicely for this too.

Lacking the ability to make holes for screws and tap them, make the holes for the shafts
a bit deeper and wider than the 1/4" size, then fill with silicone rubber. Now you have a flexible
coupling. You can always put solid couplers with set screws on either side, unless ur tight for space...

                         _-_-bear

What sort of circuit are you planning to use?  Just curious.

High pass T is a bad choice.

Another method is to start at an early age and take apart tons of useless pieces of test gear and old rigs.  Save all the parts and pieces, you'll never have to order any parts again.

"Hillman 48" Red Driveway Marker" $2.48 at Lowe's.
a just over 1/4" diameter fiberglass rod, last one I bought 5 years ago was, anyway.

thanks for the replies.  The tuner / tuners   one will be link coupled the other 2 will be base mounted at a few inverted l's .  i have a lathe so turning rod down is not a problem i guess im more looking for the barrell with the two allen screws to join them.

you have a lathe?

Make ur own, unless you need flexible??
Very EZ on a lathe.

Drill press will make ur set screw holes.

                          _-_-