HFU HF Underground

Technical Topics => Equipment => Topic started by: Zoidberg on August 10, 2015, 2011 UTC

Title: I've added a few equipment videos
Post by: Zoidberg on August 10, 2015, 2011 UTC

Well, dang me.  After a couplafew years of just using portables, I dug my Palstar and tabletop gear out of the closet intending only to photograph it for selling.  Then I made the mistake of hooking everything up just onnne laaasssttt time... now I'm hooked again.

So I made a few videos for one of my YouTube channels (https://www.youtube.com/playlist?list=PLDSpWbz7DYVTL3pJpuMf2z6VN_UHWVAwL).  Nothing is monetized, no ads, Paypal begging or spam links.  I'm putting these up out of appreciation for the many freebie YouTube videos I've enjoyed by other folks.

Here they are:

• Demo of a quick 'n' dirty passive outdoor stealth loop (https://www.youtube.com/watch?v=jwsN6BkJmO4).  Works great in my noisy suburban area, and it's so cheap I won't mind if the apartment maintenance crew find it and tear it down.  Much better than the various random wire and low dipoles I've tried in this area.  I plan to do another illustrating the components and construction, but it's really simple stuff and you probably already have the bits lying around somewhere.
  
  Palstar SP30b speaker vs. Radio Shack Optimus XTS 3 cube speaker (https://www.youtube.com/watch?v=9o_tQZDD8vc).  Both are good, much better than most built-in speakers, each has unique qualities.
  
  Radio Shack DSP 40 outboard digital signal processor/noise reduction unit (https://www.youtube.com/watch?v=F5PW1W42yUw).  This 1990s vintage doodad seems crude by today's standards, but is useful for CW and minimizing heterodynes with an auto notch filter, and a decent value if you can find one used for well under $50.  Don't pay more than that, tho', it ain't that great.

And an antenna demo I hope to improve on later as time permits.  I want to build a larger version, and do a video illustrating the construction (which is really easy anyway):

• The Villard noise cancelling loop (https://www.youtube.com/watch?v=32Hy0RAnkBk).  A cheap, easy to make, crude but incredibly effective supplement to reduce manmade static with small portables.

Let me know if the videos don't address something you're interested in, or if you have other suggestions.  I'll try to squeeze those in.

Title: Re: I've added a few equipment videos
Post by: ChrisSmolinski on August 10, 2015, 2019 UTC

Thanks for the videos. That passive outdoor loop was doing pretty well!

Title: Re: I've added a few equipment videos
Post by: Zoidberg on August 10, 2015, 2039 UTC

Yeah, I think I found a sweet spot in the yard where the loop nulls the worst local RFI.  The rest is up to propagation.

It seems mostly sensitive to sky wave, so it's not a great MW loop, but is very good on HF up to around 10 MHz.  It's working best without a ground - the ground was introducing RFI below 4 MHz.  Now I can hear WWV on 2500 surprisingly early, usually before dark even in summer.

I also removed the ferrite chokes from the TV cable feed line.  It was actually worsening the white noise.  Just one of those things you have to experiment with.  The cable runs right next to a couple of outdoor air conditioners on concrete pads, so I thought the ground wire and ferrite chokes might help, but the antenna is doing better without those.

Title: Re: I've added a few equipment videos
Post by: redhat on August 12, 2015, 1345 UTC

Thanks for sharing!

+-RH