++++++++++++++++++++ Date: Wed, 29 Jan 2003 10:09:11 -0800 From: Wayne Burdick Organization: Elecraft To: Elecraft Subject: [Elecraft] KAT100 ATU and floor tile Based on our tests, the KAT100's relay noise is about the same as the noise produced by the LDG 100-W ATU. This is not surprising since both use the same basic type of relay. Large relays are needed at high power levels. Since the KAT100 retunes instantly (in effect) on band change, the relay noise is much less of an issue for the KAT100 than it is for the LDG tuner, which must be re-tuned each time. Still, an acoustics expert we know suggested that a significant reduction in relay noise might be obtained in the KAT100 by simply installing pieces of inexpensive, self-adhesive, rubberized floor tile above and below the PC board. I've been trying to find time to do this experiment myself, but I've been too busy doing things that involve conductors. No time for insulators. So, I thought I'd pass on the idea to see if anyone (a) cared about the relay noise, and (b) wanted to experiment with sound-dampening materials. The acoustics expert, who is also knowledgeable in home maintainance, said that the needed materials were available at very low cost at Home Depot ;) Please let us know if you try any sound-dampening experiments. 73, Wayne N6KR ++++++++++++++++++ Date: Wed, 29 Jan 2003 15:18:46 -0700 (MST) From: Gary Hembree Subject: Re: [Elecraft] KAT100 ATU and floor tile To: n0ss at earthlink.net, Elecraft at mailman.qth.net What you are trying to do is damp the acoustic vibrations of the top and bottom panels. Most of the surface will probably have to be bonded to the "damper", er floor tile. Been there, done that, in the modern vernacular. Since the panels are magnetic perhaps refrigerator magnet material bonded to the tile would provide enough damping when the (removable) composite is attached to the panel. 73 Gary, N7IR DM43bi ++++++++++++++++++++ Date: Wed, 29 Jan 2003 14:37:25 -0800 From: Wayne Burdick Organization: Elecraft To: Tom Hammond Cc: Elecraft Subject: [Elecraft] Re: KAT100 ATU and floor tile Tom Hammond wrote: > > HOW WELL must they be 'stuck' to whatever it they'll be 'installed' > to? Just concerned of potential problems of removal later. I'd stick them to the top and bottom covers only. No harm done in that case. Wayne ++++++++++++++++++++ From: "Stuart Rohre" To: "Wayne Burdick" , "Elecraft" , "Tom Hammond" Subject: Re: [Elecraft] KAT100 ATU and floor tile Date: Wed, 29 Jan 2003 16:55:39 -0600 Two ways to attenuate sound: Absorb it in sufficiently great transmission loss material such as carpet tile, rough side toward sound source, and near enough to not allow the sound to spread much before its trapped, and increased density of the case by such as installing sides of lead, or a double box with heavy material like sand in between. The TL (transmission Loss) of building materials is often given on the box of ceiling acoustic tiles, carpet tiles, etc. Look up key words "Acoustic Transmission Loss" on google.com for industry white papers on how to pick acoustical attenuation materials. 72, Stuart K5KVH ++++++++++++++++++ From: "George, W5YR" To: "Gary Hembree" , , Subject: Re: [Elecraft] KAT100 ATU and floor tile Date: Wed, 29 Jan 2003 17:18:26 -0600 Just a thought: Damping vibrations of a plate can effectively be done with mass loading rather than with a flexible material. For example, a popular and common "sound deadener" product for aircraft consists of small sections of lead sheet about 1/8" thick backed by an adhesive layer for attachment to the aircraft fuselage or whatever. This mass loading reduces the resonant frequency, greatly increases the damping factor and is usually very effective. 73/72, George Amateur Radio W5YR - the Yellow Rose of Texas +++++++++++++++++++ From: "Stuart Rohre" To: "George, W5YR" , "Gary Hembree" , , Subject: Re: [Elecraft] KAT100 ATU and floor tile Date: Wed, 29 Jan 2003 17:31:13 -0600 Yes, George is right, the lead can be very thin for the effect it gives. Lead foil that sticks on is a commercial product, (or was) a few years back. Although not lead, copper adhesive shielding tape does add some mass. -Stuart K5KVH +++++++++++++++++++ Date: Wed, 29 Jan 2003 23:33:35 -0800 From: Phil Wheeler Organization: Outstanding To: Wayne Burdick Cc: Elecraft Subject: Re: [Elecraft] KAT100 ATU and floor tile Wayne Burdick wrote: >So, I thought >I'd pass on the idea to see if anyone (a) cared about the relay noise, and (b) >wanted to experiment with sound-dampening materials. > I like the relay noise. Gives the KAT100 a nice, robust character befitting its solid design. 73, Phil ++++++++++++++++++++ From: w7qhd at webtv.net (Kurt Cramer) Date: Thu, 30 Jan 2003 10:12:47 -0700 (MST) To: daniel-k2 at juno.com (Daniel L Brinneman) Cc: n6kr at elecraft.com, elecraft at mailman.qth.net Subject: Re: [Elecraft] KAT100 ATU and floor tile The audio guys call it "Dynamat" . It has a sticky side with a flim you peal off to apply to a flat surface. There are a couple thickness avalible and a similar product in a spray can. .070" x 19.5" x 32" is $19.95 mail order from www.eastwoodcompany.com 73, Kurt W7QHD (since 1951) web page: http://W7QHD.tripod.com ++++++++++++++++++++