We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissable in your locale.

Author Topic: Ferrite Coupled Wire Antenna Test  (Read 91 times)

Offline NQC

  • Full Member
  • ***
  • Posts: 105
  • Boston,MA
    • View Profile
Ferrite Coupled Wire Antenna Test
« on: June 22, 2021, 0051 UTC »
Hey All,

I wound a quickie 280 uH ferrite bar with #24 DSC . I went with the big inductance to accommodate my "ultra light"  var cap box , which is kind of on  the low side value wise. A better/bigger var cap might do better , today was  just a quick check of a lash up.

Antenna was 40 ft run out , with another 40 or 60 ft wound on a large oat meal box  for base loading.

Taps on ferrite didn't seem to do too much so far , it seemed to like being fully at the hot end.

Also it liked being horizontal, vertical was much worse. 

The idea of doubling  it back to make it a loop put it into full short and killed everything.

2000 UTC, Sun at 45 degrees West-  so D layer most likely still in full effect.Low to moderate back round  noise, also QRN dx thunder storms ( at 200 + mi)
 
Receiver ATS 803A- sensitive and digital, but a small Fe bar inside.Narrow AM works really nice.


Test of known hyper weak New Yorkers :

570 WMCA noisy but there, slow QSB weak to sometimes fair, sort of usable.

1010 WINS  slow QSB, , mostly weak , but up to fairly usable at times.

No trace of either station barefoot.

Strong  New Yorkers :

660 WFAN weak audible on Fe, good on wire.
710 WOR   same.
880 WCBS fair on Fe , quite good on wire
1130 WBBR quite strong on wire but pretty bad QRM from a first adjacent local .

Ferrite also brought in a number of fair or stronger overloaded images from locals, WAY off of the   locals true frequency. But there were enough holes to squeak through, the DX frequencies were all clear .

Ferrite positioning kind of fussy ,but manageable.  To sum , some bugs but overall not too  bad.

Might still try long folded "feed line " scheme- maybe 40 or 60 ft top shorted , spaced at 1" . But so far , shorting back killed everything , as mentioned above. We'll see.

Also BIG progress today on 5 ft Octoloop.

K
« Last Edit: June 22, 2021, 0111 UTC by NQC »
Station main receiver : Bed springs to  blue razor blade detector to 2000 ohm cans to steam  radiator. Grid FN 42