Someone was asking for advice about hope to connect a tapping point to a big coil made from 8mm copper tube. I came up wiht this solution. The copper hook and brass thumbscrew were made from bits in my scrap bin. There is a hole so a wire can be soldered to the hook.
I wanted to avoid an extra plug/socket on the LDF1-50 coax feed from the 5.7GHz horn to the masthead transverter/PA, so I used a plastic cable gland, but there was still too much movement. This clamp bolts to the inside of the steel masthead box and holds the coax rigidly so I can plug directly into the coax relay without any danger of movement and fracture.
I found a cheap surveyor’s tripod on ebay and made up a new screw and mounting adaptor to fit a short 2 inch stub mast. The original locking screw was trashed.
KBQ is in IO80LX (Taunton) and I can often hear it, but this evening is is hugely loud.
The new 5.7GHz system is ready to mount on the dish, on top of the SCAM12 pump-up mast with the tilting 95cm offset dish and 10GHz system. I’m using a Schneider IP66 rated case made from mild steel with a powder-coated finish. I’ll be adding cable glands and a Gore-Tex breather plug, and flushing the case with dry Argon, and adding a silica gel pack before it is locked and fitted on the mast. The existing 10GHz kit is in an identical case, but I’ll be moving it to the new dish, which has a -7 to +57 degree elevation drive and well as 450 degree azimuth rotation. Initially, I won’t fit the 12W PA, as I haven’t finished it yet, but everything else is sorted and will go in the box tomorrow.
I downloaded Fusion360 this afternoon and decided to try to create a CAD model of the DF9IC heatspreaders I make. Here is the CAD version, then the real thing. Fusion360 is a fantastic piece of software and it is free for hobbyists.
The RSGB have now published my talk on their Youtube channel. Click here to view it.
The source of the presentation can be downloaded here G4DBN FT8 Talk RSGB 2018
As I have two sets of SCAM12 pump-up mast legs, one original, and one set I made, I thought to might be useful to make a cage so I could use them with a 2 inch aluminium mast for when the 90kg of SCAM12 is too much to haul about.
SCAM legs being put to good use
Simple cage with 1 inch steel box sections to fit the SCAM legs
Turned pins and snap-rings to lock the legs in place
I didn’t have any 3/8 inch roll pins so used a bit of M8 threaded bar instead. The cap bolt is to lock the cage in place during deployment.
The cage is just made from scrap I had kicking about in the machine shop.
At the top of the pole, I use a nice simple collar and slip-ring/guy plate arrangement. This is for a base-mounted rotator of course
Just finished making a WA6KBL design Pickett-Potter horn for WR90 waveguide on 10GHz. Turned from aluminium bar.
One low-tech way to measure the thickness of very thin wire if you don’t have a micrometer is to use a ruler on a flat surface (sheet of glass maybe?), and something of a known thickness several times as thick as the wire. (a drill or coin perhaps?).
Put the drill or coin on the flat surface and hold the ruler with one end on the it at the 300mm point and the other on the glass, so there is a very narrow triangular gap between the ruler and the surface. Slide the wire into the wide end of the gap and move it along towards the thin end until it sticks. Read off the distance on the ruler. Say it is 56mm and the coin is a newish 2p piece, which is 2.08mm thick.
The wire size is then 2.08 x 56 / 300 = 0.39mm.
Checking the wire with a micrometer shows an actual diameter of 0.375mm, about 4% error.
