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Monday, July 18, 2016

Building a VFO. A BIG VFO. IF options?


Once again, The Radio Gods have Spoken (TRGHS).  An off-hand comment at the Manassas Hamfest, a bit of encouragement from Pete Juliano, and the next thing you know Armand WA1UQO has sent me this beautiful National HRO dial and reduction drive. This thing is so nice... Well, put it this way: this is the first time I'm building a rig around the dial! 

Further evidence that TRGHS:  I needed something on which to base the HRO dial and a box for the VFO.  Wouldn't you know it:  That Whole Foods "grilling plank" that I bought a few weeks ago was PERFECTLY sized for this task.  Eerie, don't you think?  As for the VFO box, well TRGHS again:  pictured above you see a side view of the box from one of the Heath QF-1 Q multipliers that I cannibalized for the variable caps.    Finally, for the main tuning cap, I took another look at that old brass variable cap that I took out of a 1930's era British regen (pictured above).  It had been hopelessly stuck for a long time.   I twisted it a bit and was amazed to see that it is stuck no more.  TRGHS!  (I just need to find a suitable nut so that I can mount the old cap in the QF-1 box.)

I'm thinking that this VFO will be the heart of a general coverage shortwave superhet receiver.  I want filters for AM and SSB and I'd like it to cover 5 MHz to 10 MHz.  I've been noodling various IF possibilities, but concerns about birdies and spurs keep driving me back to 455 kHz.   I have a crystal-mechanical filter for that freq.  And a big box of 455 kc transformers. What do you guys think of this option?   

Sunday, July 17, 2016

HB2HB QSO with N6ORS -- MIN-X to BITX

That's Keith N6ORS's MIN-X transceiver.  Keith explains that it has circuitry from the BITX, the Minima and even from the ZL2BMI DSB rig.  We featured the MIN-X before, when it was still outside the box:
http://soldersmoke.blogspot.com/2016/01/n6orss-min-x-crosses-pond-on-first.html

I was on twenty today with my BITX, finishing up a rather disheartening contact with a fellow who told me that he is a "checkbook operator." I was trying to encourage this fellow to build something simple -- perhaps a Michigan Mighty Mite?  He told me that he might give it a try, but only 16 years from now, after he retires.  It was like a case of the Anti-Knack!  Then Keith N6ORS saved the day by calling in with his beautiful MIN-X HOMEBREW transceiver.  We had a nice talk -- Keith mentioned the beauty of Pete's "Blue Rig." That's HB2HB (phone) QSO #5 for me.  Thanks Keith! 

Bill,
That was great fun!
I was just tuning around and heard you mentioned the Michigan Mighty Mite
so I stopped to listen and realized it was you!
Well here was my chance for a homebrew to homebrew with 'the man' himself.
I wanted to record it but missed the chance.
Here is the Min-x boxed up. the case is made from thrown away computer cases.
It runs about 70watts on 160,80 and 40 meters and about 35watts on 20 meters.
I promise to write it up, maybe even draw a schematic. hihi.
73,
Keith N6ORS
 

Here' a short clip of the MINX in action:


Saturday, July 16, 2016

Preserving Vanguard 1


Ira Flatow of "Science Friday" was recently talking about how best to preserve important bits of the history of mankind's exploration of space.  Our old friend Vanguard 1 was mentioned several times.  It is now the oldest satellite still in space.

You can listen to the Science Friday show here:

http://www.sciencefriday.com/segments/protecting-the-historic-human-record-in-space/

They also have a transcript of the show on the same page.

SolderSmoke fans will remember the Vanguard adventures of Mike Rainey AA1TJ:

http://soldersmoke.blogspot.com/search?q=Vanguard

This seems to be the month for Vanguard:  just a couple of weeks ago, on 40 meters I spoke to Dale Parfitt W4OP. Dale was one of the first people to pick up Mike Rainey's Vanguard replica signals (see link above).

AND...

The Vanguard reproduction project came up during Eric Guth 4Z1UG's "QSO Today" interview with Graham Firth G3MFJ of the G-QRP Club:

http://www.qsotoday.com/podcasts/g3mfj

(Graham has such a great voice.  He definitely SHOULD build a phone rig!)

VIVA VANGUARD!  
  

Monday, July 11, 2016

A Light for the Poor



I thought this was really clever, the kind of innovation that can make a big difference in the lives of poor people.

Sunday, July 10, 2016

Update: PA3GSV's Amazing Mighty Midget Receiver (video)



Jan sent me an amazing update on his Mate for the Mighty Midget Mk 2 receiver project.  I'm really blown away by the skill that he brings to the mechanical phase of this project.   This is a homebrew dial-string reduction drive using the end cap from a sewer pipe as the big wheel.  Think about that.  Amazing. Jan reports that with the mechanical work almost done, he is almost ready to start melting solder.  FB Jan!  Check out the video above and the photos below.