I will have another look later, as I have to open up a rig. The two HPF spares that I have did not have beads on the ALC board. I have found examples with beads on both ends of the red wire between the HPF and LPF, and another with a different wire beaded as well. I may have pictures somewhere.
As for the bead itself, 4A6 is the name of the bead that Drake commonly used. I researched it and the exact nature seems to be known only to Tektronix and the US government. But I did find some possible equivalents, and I purchased a some via eBay some 8 years ago that look exactly the same. So they must be the same, right? Kidding... Below is the sum total of the notes I took at the time. Don't ask me to explain any of it, it's been too long. :)
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4A6 bead.
E52-3N3Y-1G0 Krystinel Corp
111-00201-062 Amperex Electronic Corp
56-590-65/4A6 Amperex Electronic Corp
84127-35 Dla Land And Maritime
60-1037-03 Crane Electronics Inc.
84127-35 Defense Electronics Supply Center
Dla Land And Maritime
190SA168 Eaton Corporation, Eaton Motor Site
9170-0894 Agilent Technologies Inc., Hewlett Packard Co
FL0004F Scientific Radio Systems Inc
57-1634 Stackpole Corp The
276-0532-00 Tektronix Inc.
276-0532-00-BA Tektronix Inc.
276-532 Tektronix Inc.
5950-00-916-8080 Bae Systems Information And
British Sarozal Ltd
Bristol Electronics has 400 of Ferroxcube 56-590-65/4A6
Special Features: Ferrite; single thru hole 0.047 inch (1.19mm) dia.; 0.118 inch (2.997mm) lg; 0.138 inch (3.5mm) dia
FB43-101 Ferrite Bead
AL=600 +/- 20 %
OD = 0.138 in / 3.5 mm +/- 0.2 mm
ID = 0.051 in / 1.3 mm +/- 0.10 mm
HT= 0.128 in / 3.25 mm +/- 0.25 mm
RFI Suppression 5 - 500 MHz
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73
-Jim
NU0C
On Mon, 22 Apr 2024 13:54:26 -0700
"Raoul Meunier via groups.io" <rmeunier@...> wrote:
Beads have also been found on one of the wires connecting to the ALC board but I need to look at one to tell you which. A: Pending until I hear from you.
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73
-Jim
NU0C
Jim Shorney