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K3, KX-1 Inductors

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K9MA

K3, KX-1 Inductors

My K3 hasn't traveled much, but if it did, I'd be very concerned about
all the inductors supported only by their leads. It seems certain that
vibration would result in leads breaking. However, there's a note in
the KX-1 assembly manual specifically warning against fastening the
inductors to the board with adhesive. (That's exactly what I was
planning to do.) Why not? I doubt the reason is electrical, unless
it's stray capacitance. The only other reason I can think of is that
those handling power might get hot enough to melt an adhesive. If
that's the case, I'd really like to find another way to secure them.
Any suggestions?

Or maybe someone can assure me that with all those K3 getting shipped
all over the planet for DX-peditions, etc., none of those wires ever
break. Ever. (I'd still take along some magnet wire.)

73,

Scott K9MA

--
Scott Ellington K9MA
Madison, Wisconsin, USA

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Don Wilhelm-4

Re: K3, KX-1 Inductors

Scott,

Read the warning on page 9 of the K3 assembly manual.
It specifically states:
"Also, do not attempt to fix the turns or coils in place with adhesives
or other materials.
Those toroids needing support have been fixed at the factory. Adding
material to the other
toroids will alter their inductance, again degrading circuit performance."

In other words, don't do that. The K2 and K1 carry the same warning as
the KX1. I have encountered some of the Elecraft legacy gear in for
repair that had the toroids fixed to the board with some kind of
adhesive, it make them a mess to work with.
There have been several K2s that I know about which have been mounted in
a high vibration environment such as the cab of an OTR truck, and the
toroid leads have not failed. The toroids were not fixed in place with
any adhesive in at least one case - I know that because I built it for
the customer.

If you do use a fixative, be aware that in the case of repair, toroids
fastened like that are very difficult to remove and the board may be
damaged in the process. I have been there, done that.

73,
Don W3FPR

On 3/26/2016 12:24 AM, Scott Ellington wrote:

> My K3 hasn't traveled much, but if it did, I'd be very concerned about
> all the inductors supported only by their leads. It seems certain
> that vibration would result in leads breaking. However, there's a
> note in the KX-1 assembly manual specifically warning against
> fastening the inductors to the board with adhesive. (That's exactly
> what I was planning to do.) Why not? I doubt the reason is
> electrical, unless it's stray capacitance. The only other reason I
> can think of is that those handling power might get hot enough to melt
> an adhesive. If that's the case, I'd really like to find another way
> to secure them. Any suggestions?
>
> Or maybe someone can assure me that with all those K3 getting shipped
> all over the planet for DX-peditions, etc., none of those wires ever
> break. Ever. (I'd still take along some magnet wire.)

lstavenhagen

Re: K3, KX-1 Inductors

In reply to this post by K9MA

For what it's worth, just my personal observations:

I drag my K2, K3 and just recently my K3S all over the place on my /p outings all the time with no troubles. Now, one thing I did do was invest in a good Pelican case for that purpose - yes, it was pricey at about $200 but still a fraction of the investment in the rigs. So when bouncing around on the floor of the pickup the rig is very well protected. I don't play soccer with them for sure, but they do get bumps and thumps here and there.

But as for the inductors themselves, they look tiny and fragile, but they're quite well supported by the leads and any vibration they may undergo looks to me like it'd be well within the plasticity of the copper wire. On my K2, I remember this when building my first one. I made sure to get the toroids as well seated onto the board as possible and they're quite secure once soldered in.

On the K2 at least, the sensitive ones have precautions built-in, there's one toroid (I think it's in the synthesizer) that's bolted down flat to the board. And the BFO toroid is secured by the resistor across its leads and held firmly in place that way. The rest are in the low pass and bandpass filters, so they're not as critical.

Don, please correct me if any of this is wrong (I'll get a review soon as I'm now on the RF board build of K2 number 2 hi hi).

In other words, it's not a problem in my experience. Things like wiring harnesses and big skeletal switch assemblies and so forth are what give problems when schlepping a rig and none of the K's use those types of construction. They're designed for portability in that way.

Just my .02,
LS
W5QD

David McAnally

Re: K3, KX-1 Inductors

In reply to this post by K9MA

I have taken my K3 (S/N 6493), KPA500 and KAT500, in padded pelican cases,
over thousands of miles on the road with no apparent problems. Of course,
this is anecdotal evidence, not before and after specification testing. But
my travel includes some of the worst Oklahoma county roads where there are
more potholes and patch bumps, than original road surface. Gravel washboard
would be smoother. If Elecraft didn't find a need for additional component
support after this many years, I trust their engineering. I worked in
mobile FM business and government radio manufacturing. Those radios
generally had no additional component support on PCBs. They were tested and
met some of the most severe vibration and temperature specification
requirements. Perhaps not a apples to apples comparison, but I don't
expect a problem with the K3 line.

David M.
WD5M

On Fri, Mar 25, 2016 at 11:24 PM, Scott Ellington <[hidden email]>
wrote:

> My K3 hasn't traveled much, but if it did, I'd be very concerned about all
> the inductors supported only by their leads. It seems certain that
> vibration would result in leads breaking. However, there's a note in the
> KX-1 assembly manual specifically warning against fastening the inductors
> to the board with adhesive. (That's exactly what I was planning to do.)
> Why not? I doubt the reason is electrical, unless it's stray capacitance.
> The only other reason I can think of is that those handling power might get
> hot enough to melt an adhesive. If that's the case, I'd really like to
> find another way to secure them. Any suggestions?
>
> Or maybe someone can assure me that with all those K3 getting shipped all
> over the planet for DX-peditions, etc., none of those wires ever break.
> Ever. (I'd still take along some magnet wire.)
>
> 73,
>
> Scott K9MA
>
> --
> Scott Ellington K9MA
> Madison, Wisconsin, USA
>
> [hidden email]
>
> ______________________________________________________________
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>

Gary Gregory-2

Re: K3, KX-1 Inductors

Since 2008 k3 #679 has enjoyed life "on the road", constantly moving from one scenic location to the next.
Nothing seems to have been shaken loose over this time.
I would think by now that if anything was susceptible to working loose it should have had a Murphy incident by now?

Elecraft it appears knew about my requirement and developed the k3 just for this style of operating....grin

73
Gary

-----Original Message-----
From: "David McAnally" <[hidden email]>
Sent: ‎27/‎03/‎2016 4:11 AM
To: "Scott Ellington" <[hidden email]>
Cc: "K3 List" <[hidden email]>
Subject: Re: [Elecraft] K3, KX-1 Inductors

I have taken my K3 (S/N 6493), KPA500 and KAT500, in padded pelican cases,
over thousands of miles on the road with no apparent problems. Of course,
this is anecdotal evidence, not before and after specification testing. But
my travel includes some of the worst Oklahoma county roads where there are
more potholes and patch bumps, than original road surface. Gravel washboard
would be smoother. If Elecraft didn't find a need for additional component
support after this many years, I trust their engineering. I worked in
mobile FM business and government radio manufacturing. Those radios
generally had no additional component support on PCBs. They were tested and
met some of the most severe vibration and temperature specification
requirements. Perhaps not a apples to apples comparison, but I don't
expect a problem with the K3 line.

David M.
WD5M

On Fri, Mar 25, 2016 at 11:24 PM, Scott Ellington <[hidden email]>
wrote:

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charlie carroll

Re: K3, KX-1 Inductors

In reply to this post by K9MA

A couple of stories regarding the travels of my K3. Earlier this month
I was on Montserrat doing the ARRL SSB contest. The day we left for
home, I had to stop at the local market on the way to the airport. As
with many things on Montserrat, the market is on a hill with a driveway
that inclines upwards in the 30 degree'ish area. When I stopped at the
market, the back gate of the car popped open and out came the pelican
case holding my K3. Three bounces later, the case came to rest. So much
for the shock test.

The same K3 has traveled around Florida numerous times in my car doing
the Florida QSO Party. That's the vibration test.

Frankly, I'm not losing any sleep over inductor failures. I'm more
inclined to fail rather than the radio. Numerous pelican-case
tripsaround the Caribbean for the K3 and even a trip to St. Croix in my
back pack. Will it ever break? Maybe, but not going to look for a
problem when one doesn't exist.

73 charlie, k1xx/vp2mmf

On 3/26/2016 12:24 AM, Scott Ellington wrote:

k6dgw

Re: K3, KX-1 Inductors

In reply to this post by Gary Gregory-2

KX1 #697 and K2 #4398 have seen a bit over a decade in my backpack,
suitcase, in the car, on airplanes, two trains, and the KX1 has made a
Panama Canal passage. Nothing has fallen off. I currently have a
plastic back cover for the KX1 by W8FGU to lighten it a little when I
get back into the Spartan sprints after it warms up. If anything fell
off, I would see it. :-) I recommend following the Elecraft instructions.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the Cal QSO Party 1-2 Oct 2016
- www.cqp.org

On 3/26/2016 12:02 PM, Gary wrote:
> Since 2008 k3 #679 has enjoyed life "on the road", constantly moving from one scenic location to the next.
> Nothing seems to have been shaken loose over this time.
> I would think by now that if anything was susceptible to working loose it should have had a Murphy incident by now?
>
> Elecraft it appears knew about my requirement and developed the k3 just for this style of operating....grin
>
> 73
> Gary

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K9MA

Re: K3, KX-1 Inductors

In reply to this post by charlie carroll

Well, 5 replies reported no problems with coil wires breaking during
transport, while none reported a problem. I guess with all the zillions
of K3's etc. traveling around, we would know if there were problems.
I'll let you know in a few months what a few thousand miles by bicycle
does to my KX-1.

Thanks and 73,

Scott K9MA

--
Scott Ellington K9MA
Madison, Wisconsin, USA

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Gary Smith-2

Re: K3, KX-1 Inductors - OT

OT... but my mother, back in 1942, after
divorcing her abusive Ex (One of the main
architects of the Golden Gate Bridge),
bicycled by herself from Philly to Key
West, by herself, took a ferry to Cuba,
bicycled around the island for a month
before returning to the mainland to take
the train back to Philly.

For those of you on Facebook, here she is
in 1942 with her bike, on the Tamiami
trail on the way there:

https://www.facebook.com/photo.php?fbid=10
202216034144692&set=pb.1304919404.-2207520
000.1459281922.&type=3&theater

Had she only had a KX-1 on her ride, I may
have had a different father...

:D

73,

Gary
KA1J

> Well, 5 replies reported no problems with coil wires breaking during
> transport, while none reported a problem. I guess with all the zillions
> of K3's etc. traveling around, we would know if there were problems.
> I'll let you know in a few months what a few thousand miles by bicycle
> does to my KX-1.
>
> Thanks and 73,
>
> Scott K9MA

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