Build a Magnetic Loop?

[BenMara]

Recently watched this vid. Now im thinking about adding a magnetic loop to my antenna arsenal (farm).


What do yall think?

Current antennas are Hexbeam (20-10m), (OMTA) Offset Multiband Trapless Antenna (vertical 40-10m) and 80m wire fed with window line (50' above ground at feedpoint).

 

[sp5it]

You can't have too many antennas

 

[2RT307]

I'm with sp5it. I've heard they are great for receiving, especially on 160 where things are so noisy all the time. My coolest antenna I made recently was a tape measure yagi for 2 meters. Ha!

Let us know how you make out.

73,
Brett

 

[BenMara]

Only problem i see is the variable capacitor. And to make it 100w+ compliant

 

[BJ radionut]

Yep Commercial Grade vacuum variable...Jennings/Comet/Russian equivalent is about your only options at that power level...100w PEP+ requires pretty high voltage like 5K VDC or possible more depending on construction.
Then mounting and tuning are other hurdles.
GL
All the Best
Gary

 

[BenMara]

Boy Vac Variable Capacitors are $$. Found this one from Palstar C600
http://www.palstar.com/en/capacitors/

 

[Captain Kilowatt]

Boy Vac Variable Capacitors are $$. Found this one from Palstar C600
http://www.palstar.com/en/capacitors/

Better get the 5500 volt rated one and don't run too much power. Vacuum variables really are the way to go with small loop antennas.

 

[BenMara]

Totally agree. i dont plan to run past 100w. 99.999% of the time on any Mag Loop

 

[BJ radionut]

Boy Vac Variable Capacitors are $$. Found this one from Palstar C600
http://www.palstar.com/en/capacitors/

Those are "Air" variables
These are Vacuum
http://www.mgs4u.com/RF-Microwave/vacuum-variable-capacitors-500.htm

https://www.rfparts.com/capacitors/capacitors-vacuumvari/vacummvariable-201to500pf.html

http://www.ur4ll.net/MLA.jpg http://www.ur4ll.net/#caps3

15-750pF 5KV 35A max dia. 108mm, max len. 200mm (incl shaft)
(measured capacity is 10-780pF)
All the Best
Gary

 

[BJ radionut]

100 watt carrier rated mag loop

 

[BenMara]

If i like the 160/80 mag loop performance, Ill most likely build one for 40/20. Can never have too many antennas on the farm.

 

[BenMara]

100 watt carrier rated mag loop

Do you have any online sources for MORE mag loop info? My ARRL antenna books is so limited for Mag Loop antenna...

 

[MicroWave]

Building a loop antenna yourself is always an option, but with most commercial antennas there is always something that doesn't fit exactly. Either they are too narrow, or they don't exactly cover the frequency ranges that you need, or there is no cable remote control, or there is a cable remote control, but the antenna is the ultimate junk, or they are not suitable for higher output power etc. It's really frustrating sometimes!

 

[BJ radionut]

https://www.k4vrc.com/loops.html

http://www.cvarc.org/resources/Tech_Articles/magnetic_loop_antenna.pdf

https://amrron.com/2015/07/24/home-made-high-power-magnetic-loop-antennas/

This should get you started...Good Luck
All the Best
Gary

 

[jon666]

i have a mfj mag loop antenna. works great i got it on a rotor to turn to catch dx. of course it is not cheap around 500 bucks