Thank you! Yes, this is commercial Mu Metal shielding, but no the same
brand. The magnetic permeability is 1,000,000 and it can be bent. See
the link to lessemf.com in the original message for purchase info. I
got $5 worth. It is fun stuff.
Leigh.
On Tue, 4 Jan 2005 3:23 pm, Stuart Rohre
Aluminum foil has very slight magnetic shielding, but there is commercial mu
metal foil that is very expensive but very good.
Thin sheet metal is cheaper and more readily found. Check it with a magnet
to see if it will work as magnetic shield. If magnet sticks it is steel or
ferrous (shield
]
To: A Walker [EMAIL PROTECTED]
CC: Elecraft@mailman.qth.net
Subject: RE: [Elecraft] Hum Coupling
Date: Wed, 03 Nov 2004 13:01:47 -0600
Hello Allen,
My guess is that magnetic fields from power transformers are either
1) being
picked up by L30, or 2) that the magnetic fields are going through
Thanks! The foil is supposed to have be very good for magnetic
shielding and so I thought I would try it, as it is small and light
enough that it could be put inaide the rig if it works. I will report
when I try it on L30.
Leigh.
On Mon, 3 Jan 2005 6:53 pm, Stuart Rohre wrote:
Leigh, most of
Leigh, most of your coupling may be magnetic, if shielding did not reduce
the RFI.
You might want to experiment with steel shim stock or even tinplate from
cans.
The easiest fix is distance: Moving the rig away from magnetic and
electric field sources of transformers as you have found.
GL,
Hello Allen,
My guess is that magnetic fields from power transformers are either 1) being
picked up by L30, or 2) that the magnetic fields are going through the cores
of L30 and/or T5, and modulating the effective permeabilities of these
cores. This will cause a modulation of inductance, and
Subject: RE: [Elecraft] Hum Coupling
Date: Wed, 03 Nov 2004 13:01:47 -0600
Hello Allen,
My guess is that magnetic fields from power transformers are either 1)
being
picked up by L30, or 2) that the magnetic fields are going through the
cores
of L30 and/or T5, and modulating the effective
In a message dated 11/1/04 8:36:41 PM Eastern Standard Time,
[EMAIL PROTECTED] writes:
I cannot help but note that the venerable Kenwood TS-930S and TS-940S
rigs had their big hunk of a power transformer mounted right next to the
PLL section - and no hum problems were apparent, and it was
Fraser Robertson wrote:
Interesting - I had complaint on air recently of having a wide CW
carrier when using a tube linear about two feet from the K2/100.
I do NOT have the problem (and I've had people listen carefully for it) with an
Alpha 86 at full power located 4 feet from the K2. For
Fraser, G4BJM wrote:
Interesting - I had complaint on air recently of having a wide CW
carrier when using a tube linear about two feet from the K2/100.
==
Exactly the problem. Rather than hum, it sounds like noise on the
sidebands of the signal -- becoming less broad as the distance
Thanks for the mu metal info, Stuart.
If Eric and Wayne don't come out with a mod for it, I'll try that.
73, de Earl, K6SE
___
Elecraft mailing list
Post to: Elecraft@mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr.
This belongs in the For What Its Worth file:
I cannot help but note that the venerable Kenwood TS-930S and TS-940S
rigs had their big hunk of a power transformer mounted right next to the
PLL section - and no hum problems were apparent, and it was NOT a
toroidal type transformer, just a
Jim, KL7CC wrote:
So, maybe the problem [hum getting into the K2's PLL] could be worth
another look, as in maybe there is another way to solve it? Could
something be done to the K2 itself to make it immune to this problem?
==
Hum coupling from the K2's power supply xfmr is not much of a
Hi
The K2 is susceptible to hum pick up. You must keep all sources of AC magnetic
fields at least 3 feet away from the K2 or the VFO will be modulated by the
hum. This has been noted many times here on the reflector. Even a high
intensity lamp too close to the K2 was a problem. Do not stack
At 10/29/2004 10:16 AM, Tom Hammond wrote:
Supplies with big trnasformers, or even small ones carrying high current,
can/will often cause hum on the K2. Best to space them a distance away.
Switchers probably won't induce hum, but might cause in-band birdies by
virtue of their switching
Actually - after toasting my internal KBT2 by overcharging with an uncontrolled
solar panel (hint hint... words for the wise) - I bought a $50 MityMite 12Ah
battery/charger from Autozone. I plug it in to charge when I'm not on the air,
and then I unplug the charging cord, and turn on the radio and
The bottom line on placement of rigs to avoid hum for Elecraft, or any other
brand, is to place the transformers and switchers as far from the rigs as
possible within reason. Use twisted pair leads from DC supplies external to
the rigs, and shield them if possible.
Alternatively (and at great
Actually, Tom switching supplies may have a worse coupling effect since they
have an oscillator going at higher frequency than the power line, in
addition to power line 60 Hz.
And, even coupling of RF between Tuner and Radio can happen. At a Field Day
one time, a tuner was placed on a Yaesu
I have an Astron 20 amp for my K2/100 and it sits on a stool UNDER the
operating table. That keeps the table clear for other things and keeps
the AC magnetic field out of the K2.
I've also got an Astron 20 amp supply that lives under the desk. You
forgot to mention that it also makes a nice
19 matches
Mail list logo
