Re: Which Litz Wire (660 / 46 or 100/44) is BetterTo Order for 7,5 Fixed Loop?


Pollock,Raphael E <rpollock@...>
 

Hi Jerry!
 
I can certainly appreciate your dilemma. I decided several months ago to follow the great work of Gary DeBock, Steve Ratzleff and other FSL experimenters rather than take on an FSL project myself. My decision was based on my lack of electronics knowledge and measuring equipmenht, time constraints, concerns about how well the ferrite bars from Eastern Europe would work, as well as the reality that I was very happy with my monster ferrite antennas. I backed into these antennas several years ago, almost by serendipidity. I was able to pick up an Eton E1 for $225 when Circuit City went kaput. I looked for antenna options for the E1 which does not have an internal ferrite bar antenna. I had an old wood frame box loop (3' x 3') I built in the late 1990s using an article from Pop'tronics from then, and had gone through a phase of early MW dxing in the 1980s and had some of the IRCA and NRC antenna manuals, the Joe Carr loop book, and also did a lot of research on the web (crystal radio sites) and the various Yahoo radio and antenna hobby clubs. I came across several references to Stormwise.com, went to their site, found their plans for an AM radio (still on their web site) and ultimately adapted the antenna component as per a synthesis of the above research. At that time Stormwise had a 27" monster ferrite bar (125 mu) suitable for a ferrite bar loop and so I purchased it ($55 if my memormy serves me right). In reading about Litz wire in the various crystal radio sites as well as email communication with Dave Schmarder I decided to go with 660/46 because of the skin conductivity effect.
 
That antenna worked out really well for the E1 in a direct coupled format. I was at Fry's Electronics last summer with my father-in-law and they had a refurb Sat 750 for $120 so I purchased it on a lark. The 27" ferrite bar antenna worked well as an inductively coupled antenna with the 750 but was a bit cumbersome so I purchased the 19" 125 mu ferrite bar from Stormwise ($37 as I recall) and made another monster loop just for inductive coupling (no secondary pick-up coil). I have been very happy with this antenna, which can be seen in action on a You Tube video I made some time ago--it can be found by searching under the term "ferrite rod antenna". I then came across an article by John Bryant and friends about their monster ferrite exoperiments. I found this on the Ultralite web site--a really interesting report. They were particularly happy with a 48" ferrite bar antenna that they made and tested, so I purchased a 48" 125 mu ferrite bar from Stormwise for $100 and am working on this antenna at the moment. I don't know if the extra length will make a difference in my hands--there is not much difference between the 19" and the 27" ferrite bar antenna regarding pick-up or inherent sensitivity. The 19"er is quite a bit lighter in weight and easier to transport. Unfortunately Stormwise does not seem to be selling any more 125 mu ferrite bars so I don't have a good source for one-piece monster ferrite bars anymore--glad I bought these three when I did. Sarmento, a Brazilian MW DXer, has some really nice You Tube videos of smaller multiple rod ferrite bar antennas made by bundling 15-20 smaller ferrite rods together.
 
I am not certain but I think that Gary or one of the other Washington Ultraliters has both an 18" monster ferrite bar antenna and also a MW FSL so he may be the only person who will be able to do the head-to-head comparison you are desiring. I would be very curious as well, especially because I have hardly scratched the DX surface with the current set monster ferrite antennas, and so I don't yet know what I may even be missing!!!
 
Hope this helps--
 
Raph Pollock
 

From: ultralightdx@... [ultralightdx@...] On Behalf Of Jerry Popiel [jerry_popiel@...]
Sent: Thursday, July 21, 2011 4:07 PM
To: ultralightdx@...
Subject: RE: [ultralightdx] Which Litz Wire (660 / 46 or 100/44) is BetterTo Order for 7,5 Fixed Loop?

 

This is indeed a dilemma. If I want to build the 7.5 inch Ferrite Antenna, the less sensitive 100/44 wire will need to be used due to width restrictions.  If I try to construct  a larger (much more expensive) FSL Antenna, or use a larger 18 inch Ferrite Rod, than the more sensitive 660/46 Litz wire is the better choice.  I like the idea of an Inductively Coupled Loop because no internal mods of the PL 380 would be required, and it could also be used with other radios such as my G3.  Maybe order a roll of BOTH Guage Litz wires for now?
 
Are there any comparison Tests or Data on how the 18 inch Ferrite Rod Loop compares to Gary's 7.5 inch Ferrite Rod?  And with a lot more Folks now  building and experimenting with FSL Loops, are there going to be any future detailed writeups on building one of them, which I guess also depends on the availability on the internet of those Russian Ferrite Rods? 
 
Thanks
Jerry 

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