My Pacemaker Speed Graphic is presenting some difficulty in the realm of cable releases. Of the releases I have tried (all tapered) only one fits the body release (but not strong enought to trigger it) and none fit the shutter, which is where I really need it. I have been told that I need an american-style older non-tapered straight thread release, but am having some dificulty finding one. I have located two companies that sell either this product, or an adapter to the straight thread, but they are either out of stock, or not responding, respectively. If anybody knows of a source of these type of cable releases, please assist. That auction site has been of no use.

What lens/shutter do you have?

Answer Les. I must have twelve releases here and while some work better then others they will all screw into every shutter I have here except turn of the last century pneumatic bulb only.
Body releases don't tend to work very well with a cable attached unless they are silky smooth, and that is rare and requires removal of the leatherette and a complete service of the internal parts and reassembly and lube etc... Live without it and figure out the front release problem. Hard to say without seeing it, but there is a lot of stuff out there fitted to these cameras.
have fun

It is a Graphex (Wollensak) shutter on a 135mm Optar.

Standard release oughta work OK. Don't know what the problem could be unless something is weird with the threaded part on your releases or the shutter itself. Any signs of damage? It could possibly be swithched out for one that works also so you have more options...

Problem solved with an old prontor straight thread cable release, but even that was a bit tight.