Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old September 27th 17, 06:34 PM posted to rec.radio.amateur.moderated,rec.radio.amateur.misc
external usenet poster
 
First recorded activity by RadioBanter: Aug 2014
Posts: 777
Default [KB6NU] Would you buy alligator clips from this company?


KB6NU's Ham Radio Blog

///////////////////////////////////////////
Would you buy alligator clips from this company?

Posted: 26 Sep 2017 12:55 PM PDT
http://feedproxy.google.com/~r/kb6nu...m_medium=email


This appeared in my inbox about an hour ago:
Besked fra afsender:

â—Ž

â—Ž

forget the above information
★★★★★★★★★★★★★★★★☠…★★★★★★★★★★★★★★★★⠘…★★★★★
Nice day, dear friend-
Hope this email find you well-
This is Ana, a girl from China shenzhen, manufacturer of audio connectors,
dc connectors, alligator clips, test cable,Â*and rf connectors for 13 years.
After saw your website, I thought you might be interested in our product as
below picture showed,
https://ae01.alicdn.com/kf/HTB1b2G.S...Xq6xXFXXXV.jpg
would you like to get some samples for testing , my friend ?We still have
many other models, i can send you our more information if its okay for
you,Â*ODM & OEM available since 2001
dear friend -Im here waiting for your reply-
all email send to and and

Contact person : Ana

whatsapp :+86-18126184197

E-mail:






wechat: yibaokeji121

Skype : michael.zhaoyanhui

web :
www.koko-go.com
★★★★★★★★★★★★★★★★☠…★★★★★★★★★★★★★★★★⠘…★★★★★
forget the below information

â—Ž

â—Ž

So, would you buy alligator clips from this company? Im tempted to ask for
samples, just for the heck of it.

Another odd bit of info is that the sender of this email is
. danhostel.dk, as the name might imply, is a chain of
hostels, offering holiday accomodations in Denmark.

The post Would you buy alligator clips from this company? appeared first on
KB6NUs Ham Radio Blog.


///////////////////////////////////////////
Why 50 ohms?

Posted: 26 Sep 2017 12:02 PM PDT
http://feedproxy.google.com/~r/kb6nu...m_medium=email







I often get asked by newcomers why we use 50Â*Ω coax in amateur radio, while
cable TV uses 75Â*Ω coax. I didnt really have a good answer until I read the
following tweet from GB, KG4GVL, and the reply from Dave, KJ8U:


GB HoytÂ*@KG4GVL

Can anyone give me a sound electrical reason why we design antenna systems
around 50 Ohm impedance?


















DaveÂ*@KJ8U

Long answer microwaves101.com/encyclopedias/…








The executive summary of the long answer on Microwaves101.Com is that for
coaxial cable with an air dielectric, the lowest loss is at about 77Â*Ω.
Air-dielectric coaxial cable can, however, handle the most power whenÂ* its
characteristic impedance is about 30Â*Ω. Youll find all the math at the
Microwaves101.Com link above.

Hams want coaxial cables to both handle a fair amount of power and have
relatively low loss, so whoever chose 50Â*Ω as the amateur radio standard
did so because it happens to be about halfway between 30Ω and 77 Ω.

Nowadays, we rarely use air-dielectric coax. Instead, we use coax with a
polyethylene dielectric. This increases the power-handling capability of
the coax. Not only that, a coaxial cable with polyethelene dielectric has
the least loss when the characteristic impedance is 51.2Ω.Â* How lucky is
that!

By the way, this line of reasoning also explains why 75Â*Ω is the standard
for video and cable TV. These cables dont have to handle a lot of power, so
minimizing loss is the most important consideration in these applications.

The post Why 50 ohms? appeared first on KB6NUs Ham Radio Blog.


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[KB6NU] Make a 2.4 GHz Yagi with paper clips and popsicle sticks KB6NU via rec.radio.amateur.moderated Admin Homebrew 0 March 30th 17 06:31 PM
WTB: HC/6u sockets with xtal clips Tio Pedro Homebrew 1 February 7th 09 07:52 PM
ALLIGATOR CLIP TEST LEAD ADAPTOR Bill Turner[_2_] Boatanchors 0 January 16th 09 04:48 PM
FA: 2 BNC Male to Alligator Clips RG-58C/U, 60 inch, Travis Homebrew 0 July 30th 08 12:13 AM
SK-506 chimney clips jack leishman Homebrew 0 March 22nd 06 06:05 AM


All times are GMT +1. The time now is 04:39 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017