Tag: Aerial

Recyclo-Cantenna

A recent article on the popular Hack-a-day website showed readers how to build a very simple ADS-B ‘Cantenna’ to use with their SDR USB dongle radio

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Type of wire for a centre fed wire dipole.

Going to have a go at making a half wave centre fed wire dipole for 20mtr.

I have all kinds of copper wire in my shed mostly pvc insulated but I do also have some bare copper but its quite thin single strand at around 0.5mm.

I see some commercial types on the likes of ebay using what looks like stainless guy wire for elements.

Are there any do’s and donts re wire spec for antennas…my radio is rated at 100w…

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ARRL Suggests FCC May Need to Intervene to Ensure Effective Antenna Rights

Commenting in response to an FCC Public Notice (DA 17-1180) released last month, ARRL addressed the extent of Amateur Radio’s response to recent hurricane disasters and efforts needed to expand the use of Amateur Radio services when it comes to planning, testing, and providing emergency communication. The comments point out that Amateur Radio not only has been “far more than a hobby;” it is a u…

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Using Spark Plugs for a lightning grounding?

Hi Folks,

I’ve read that spark plugs can be used to ground in cases of lightning. The terminal of each plug connects to each side of a balanced feed and the body/gap connects to ground. First, I read that a strike is typically 5,000 – 50,000 amperes and they have recorded strikes of 100,000 amperes. The voltage is around 4.5 kV.

I was interested in how they would behave in a strike and had a suspicion that the center electrode in the insulator may have high voltage but lower current,…

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InnovAntennas release 4/2m dualbander

InnovAntennas today released the first in a new range of dual band Yagis covering both 4m and 2m bands. The first in the range is a 12 element which has 5 active elements on 70MHz and 7 active elements on 144MHz with a single feed point and 2.4m boom

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End fed and common mode

Since an end fed wire is the best antenna that I can have at my location, I’m trying to understand better how it works, so that I can hopefully improve its performance. It does “work”, but the term is relative. It kills my computer USB keyboard sometimes, which I believe is due to common mode current.

Subsequently, I thought I would implement a 1:1 unun common choke, but I don’t know where. I read online that a good place is between the radio and the 9:1 unun, right before the 9:1. In…

End fed and common mode For the full article, https://forums.qrz.com/index.php?threads/end-fed-and-common-mode.594924/

My final(?) attempt to improve Cobweb bandwidth

I described some modifications of the G3TXQ Cobweb in the other thread. I called them Mark 1 and Mark 2. I built Cobweb Mk.1 myself and Elias, EB5KT, built Cobweb Mk.2. Mark 2 was better because it had wider bandwidth on the 10 m band. However, bandwidth improvement came at a cost. The radiation patterns of the modified Cobwebs were closer to a bidirectional dipole-like pattern. Since that time, I modeled a number of other modified Cobwebs but until recently all my ideas did work very well….

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