Monday, 30 December 2013

Vacuum Capacitor - From Russia (Via Ukraine) With Love

For a long time, I've been looking out for a decent vacuum capacitor to reliably tune my 20m magnetic loop antenna.

At long last, and just before Christmas, I 'won' an ebay auction for an 'new old stock' vacuum capacitor, sold by stas3105, based in Kiev, Ukraine.

Now, you may feel a bit nervous dealing with Ukraine.  Happily, I can reassure you in that I've only ever had very good service from several Ukrainian sellers.  There seem to more ham operators in Ukraine than any other country on Earth!

Wow!  These Russian capacitors are huge!  They have a very good reputation for quality, according to fellow hams across the EU.


The capacitor, far from being some dodgy second-hand unit, really is in brand-new condition, liberally covered in protective grease and oil.  According to the accompanying leaflet,  it was made in 1990. It set me back a very modest £69, including the necessarily hefty carriage bill, the item being rather delicate.  I obviously managed to get a good price by buying just days before Christmas, when there was less interest than usual in this stuff.  It only took about a week to get here.

I happened to have a lot of tinned copper braid in the junk box, so this was ideal to make the connections, using jubilee clips to secure the braid to the capacitor tips.  It took a few minutes to find the correct tuning for the loop. 

WSPRing across the globe - 5W, 75cm off the ground in the kitchen!

Once tuned-up, the loop ran on WSPR for a few hours at 5W.  Unfortunately, the internet was on the blink most of the time, so only those stations hearing me are recorded for the most part.  Spectacularly, and again it was missed by broadband outage, I heard a signal from ZK1DRP in the Pacific Cook Islands.  That's pretty good going for a tiny magloop working indoors!


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