Re: Gluing multiple ferrite rods?


Gary DeBock
 

Thanks Steve,
 
I'm happy that you enjoyed reading the Sony SRF-39FP loopstick transplant article.
 
Loopstick experimentation is lots of fun, and it doesn't require much $$ if you can salvage some ferrite bars from old classic radio portables on eBay, like the "Channel Master Super Fringe" (most of which don't work any more, sparing you the distress of condemning an operational radio :-) One or two of these old ferrite bars can provide enough ferrite to really boost the sensitivity of almost any ULR, once new coils are wound matching the stock loopstick coil inductances.
 
Loopsticks are the natural antennas of Ultralights, combining great portability with decent DXing performance. Unfortunately the Chinese factories have recently cut a lot of corners in loopstick quality, but that won't stop serious DXers from designing and building the high-quality loopsticks that we deserve :-)
 
73, Gary DeBock      
 
In a message dated 5/21/2010 8:32:18 A.M. Pacific Daylight Time, cbyjeqjd@... writes:

 



Thank you for your time Gary. These past couple days I've been steadfastly searching and reading articles pro and con, but mostly pro. I read a number of your interesting modifications at DXer.CA - very intriguing as here with the newer Sony and Tecsun chips. Some of it is Greek to me and some I understand from my limited crude old time mods. These ultralights and the work some of you guys are doing is bringing a new spark. The link with the Sony SRF-39FP is excellent, I feel like I might be able to establish a wonderful capability to optimize ("supercharge") without the old math formulas which were always intimidating. It will still cost as I will need a good LCR meter which I kinda assumed. The Stormwise looks pretty awesome but if money is a problem I know now I have choices on eBay.

Thanks much...

Steve

--- In ultralightdx@..., D1028Gary@... wrote:
>
> Hi Steve,
>
> Thanks for your interesting question about combining ferrite rods together,
> to make more sensitive loopsticks.
>
> Back in the early days of the Ultralight radio boom, I was fascinated by
> the challenge of making a tiny analog Ultralight radio (the Sony SRF-39FP
> "Prison Radio," a member of the SRF-59 family of CXA1129N chip-based radios)
> as sensitive on AM as the Sony ICF-2010 model. The detailed experimentation
> involved taping ferrite bars together to make longer composite loopsticks,
> then rewinding the coils to match the inductances of the stock loopstick.
> The experimentation used salvaged ferrite bars from old vintage radio
> loopsticks, and was very successful in boosting the sensitivity of the SRF-39FP
> past that of the ICF-2010 , as described in the article posted at
> _http://www.mediafire.com/?zmenm1zdmmw_ (http://www.mediafire.com/?zmenm1zdmmw) .
>
> The newer ferrite bars (such as the type 61 7.5" models sold by Amidon)
> typically are too expensive to be practical in making composite loopsticks
> this way, but fellow Puyallup, WA resident Guy Atkins has had excellent
> results using the larger and longer ferrite bars sold by Stormwise, which would
> probably outperform any long composite loopstick. Guy recently made an 18"
> loopstick PL-380, which is an outstanding DX performer:
> _http://www.mediafire.com/file/imykf4ndnnj/pl-380_18inch_front[1].jpg_
> (http://www.mediafire.com/file/imykf4ndnnj/pl-380_18inch_front[1].jpg) .
>
> 73, Gary DeBock (in Puyallup, WA, USA)
>
>
>
>
> In a message dated 5/20/2010 3:43:39 A.M. Pacific Daylight Time,
> cbyjeqjd@... writes:
>
>
>
>
> Hi folks...
>
> I've done some makeshift improvements with a few radios over the years but
> I've always wondered, does gluing 2 or more rods together by the ends
> deteriorate their capability compared to 1 long one of equal length? Buying
> longer ones apparently increases the price significantly compared to shorter
> ones, if they could be glued together.
>
> Steve
>

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