[Elecraft] BL2 choking Impedence measurements?

[CUTTER DAVID]

Ian

Our friends over the pond (K9YC etc) extoll the virtues of type 31 material

but I have yet to see this in European stocks, (I was disappointed to see

none at Friedsn) do you know of an easy source?

Reading through your latest choke missive, I notice that nice obround

shaped core from Farnell but looking up the Fair-Rite catalogue I notice
they

have a slotted version made for multiple cable entry: 2643165151 which

would lend itself even more to the quest for low capacitance between turns.


Can you see anything against this?

What is going through my mind is how the amateur fraternity could persuade

a distributor in EU to stock these and the type 31 cores.

Further to your careful layout within the core, I'm sure I've seen a guide
that

would help to keep things in order - I think it's a plumbing part, I will
continue

to look.  I think mounting the chokes on a piece of ply with clamps would
give

it rigidity and an easy mounting method.


Ready-made cables would make these chokes very easy to put together but the
nice microwave ones I bought surplus recently have mostly N type connectors:
another reason for that slotted type of core.

I haven't seen measurements done on a solenoid coil of coax which is very
easy to do using up surplus lying around.  If the turns are slightly
separated, that should help with self-capacitance.

73

David
G3UNA


> Follow the link below for a reasonably short summary, and then go on to
> read Jim's much longer treatise:
> http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v1.pdf
>
> --
>
> 73 from Ian GM3SEK
> http://www.ifwtech.co.uk/g3sek