I had an original Cushcraft A3S, which had trap coils and screws coated
with the hard epoxy. The screws clearly weren't going to turn, and I
never saw any evidence of poor connections, but I suppose the material
could have yielded. Replacement traps I got from MFJ (after insect
damage) had no coating on the traps, loose screws, wires wrapped
backwards, etc. They were junk. I would not recommend buying any MFJ
Cushcraft or HyGain antennas.
I currently have an old Cushcraft D40, also pre-MFJ. I'm pretty sure
they have shrink tubing over the coils, though there may be epoxy under
that.
Unless you see evidence of poor connections at the screws, I would leave
them as is. If the epoxy looks like it's suffering UV damage, it might
be worth covering it with UV-resistant shrink tubing or tape. I wouldn't
think the stray capacitance would be as critical is it is in traps.
My D40 has been working for over 25 years, though I did have to replace
the center insulators, and the elements aren't quite straight any more.
73,
Scott K9MA
On 9/12/2020 5:07 PM, RVZ via TowerTalk wrote:
Hi Guys,
I purchased a Cushcraft XM-240 which was new in the box but was made about 10 years ago. The label on the box says "Cushcraft XM-240", and doesn't mention
MFJ, so perhaps it was made by Cushcraft. My questions pertains to the 4 loading coils. I believe the loading coils made by MFJ have heat shrink
tubing over the coil, is that correct? The loading coils on this XM-240 don't have heat shrink tubing over them, rather the coil is covered with a thick shiny black
epoxy which is very hard. The epoxy has really sealed up the coils and self tapping screws that connect the coils to the aluminum tubing. I believe the epoxy
would be rather difficult to remove so I'm wondering if I'm likely to have reliable results using the traps "as-is" for a couple years, or if I should remove the
hard epoxy from the self- tapping screws now and replace them with screws, nuts, and lock washers? If I do replace the screws, should I cover them with more
epoxy, use heat shrink tubing, or both? Thanks & 73, Dick- K9OMWisconsin
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Scott K9MA
k9ma@sdellington.us
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