Re: Antenna Tuner


Arv Evans <arvid.evans@...>
 

The inexpensive "universal testers" that sell for less than $25 on Ebay will evaluate most toroid cores for inductance.  Just add 5, 10 , and 20 turns,  measure inductance, then do rhe math to reveal  probable  characterestics.  Not super accurate, but should get you in the ballpark.

Further tests can be done to find core saturation, heat rise, and q-factor.

All this does require some knowledge of electronics and maybe a little physics.

On Sat, May 22, 2021, 3:52 PM Michael.2E0IHW via groups.io <blumu=btinternet.com@groups.io> wrote:
No surprise, Lee

Although adjunct to  Q'Labs topics, the big conundrum
with toroids remains : how to know!

I have yet to discover the one-true-posting which will enable me to
measure and evaluate, *with simple means*, the jumble of toroids
languishing in my treasure-box...

Trystan : over to you!

Michael


On 22/05/2021 22:15, Leland L. Bahr wrote:

This is a piece of crap.  The toroid is fake and not even a type 2 red core, just painted red.  This thing is super inefficient.  Most of your power will go into heat.  I threw mine away.  Pure Junk.  A waste of money.

Lee, w0vt

On 5/22/2021 1:25 PM, K2DB Paul Mackanos wrote:
Thx, I just ordered one !
Paul K2DB

On Sat, May 22, 2021 at 11:41 AM Trystan G0KAY <trystandavies+nodirect@...> wrote:
Here's the one I got, it arrived in around ten days from China to the UK:

https://www.banggood.com/1-30Mhz-LED-VSWR-DIY-Manual-Antenna-Tuner-Kit-For-HAM-RADIO-+-CW-QRP-Q9-BNC-Interface-p-1253567.html

Trystan
G0KAY


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