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Well, the assembly manual leads me to think otherwise.
It stresses conductivity, getting all components to the same potential, etc. When I look up these mats on websites, I find two kinds - conducting and nonconducting. The wording in the manual says to me to get the conducting type. Ken K5WK Yuma, AZ _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Ken817821
Right! get a conductive mat, with a HIGH-RESISTANCE per square.
Mark _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Ken817821
If you're going to do this, why not save more $$$, and just grab some
aluminum foil, and spread it out on the table? I can't *imagine* why not a single one of those smarty-pants engineering types has ever thought of this, and instead, specify special anti-static mats. :-) For whatever it's worth, I bought my mat for ~ $29 from CyberGuys: http://www.cyberguys.com/templates/SearchDetail.asp?productID=451 It was pretty nice, although I don't have much to compare it to. Be careful, okay? 73, Steve NN4X On 4/2/08, Ken <[hidden email]> wrote: > Well, the assembly manual leads me to think otherwise. > > It stresses conductivity, getting all components to the same potential, etc. > When I look up these mats on websites, I find two kinds - conducting and nonconducting. The wording in the manual says to me to get the conducting type. > > Ken K5WK > Yuma, AZ > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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If you use a bright lamp over the table as I do, the glare from the foil
would not be good. As has been said before, if you are going to spent the money on a nice Elecraft kit, spend a few extra bucks and get a anti static mat. Just my opinion. 73, Tony W7GO 73, Tony W7GO S Sacco wrote: > If you're going to do this, why not save more $$$, and just grab some > aluminum foil, and spread it out on the table? > > > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Ken817821
All surfaces contain a charge except those that are designed not to. Non-conductive material will not hold or generate any electrical charge. Therefore, it is desireable to use this material when storing or transporting devices that can be damaged by Electro Static Discharge (ESD). You want a conductive ESD mat! These are made by a number of manufacturers a route the static away from your body, shirt, radio, ect to ground. It also keeps it from damaging sensitive electronic components inside the radio. These come in a variety of materials and prices. By using the wrong surface, you can do more damage than you would on a normal table top. One hint! Run the humidifier! Dry air increases static generation. 73 Mike K2 SN 4841_______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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I hate to add my 2 cents but as far as a humidifier, you want above 30
percent humidity, an air ionizer would be the next step up after that, a lot of the larger RF transistors used in my workplace are especially sensitive, and it is a requirement to run an ionizer to prevent gate damage. Matt KD8DAO _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Michael Harvey
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In reply to this post by Michael Harvey
I'm not convinced - I thought ESD packaging is designed to conduct
across its inner surface, therefore preventing the build up of static and charge on one part. -- Mathematics is the language with which God has written the universe. -Galileo Galilei, physicist and astronomer (1564-1642) On 2 Apr 2008, at 21:34, Michael Harvey wrote: > All surfaces contain a charge except those that are designed not to. > Non-conductive material will not hold or generate any electrical > charge. Therefore, it is desireable to use this material when > storing or transporting devices that can be damaged by Electro > Static Discharge (ESD). _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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On Wed, Apr 2, 2008 at 5:38 PM, David Ferrington, M0XDF
<[hidden email]> wrote: > I'm not convinced - I thought ESD packaging is designed to conduct across > its inner surface, therefore preventing the build up of static and charge on depends on the type of ESD packaging, esd protected or esd resistant, the pink plastic material will not develop a charge, while the shiny bags or black foam are conductive protecting the device. there are also the black plastic boxes which will not generate static. Matt Kd8dao _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Would not it be nice... if someone measured the IMD dynamic range of the K3 with the interfering signals placed within the bandwidth of the first IF (roofing) filter? Or has that one already been published somewhere? Or is that impossible to measure? Arie PA3A _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Nobody makes 500 Hz IMD dynamic range measurements - they are meaningless but that is what it would take to get both interfering signals inside the passband of the 2.7 KHz roofing filter. Sherwood has made some very close in blocking dynamic range measurements but I do not know if he has released that data. The essence of the private e-mail is that even at 1 KHz the limiting factor in the K3 is not blocking but phase noise performance of the K3 and/or the interfering signal. The final analysis is that key clicks and phase noise from signals less than 1 KHz way would be more of a problem than either IMD or blocking. 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Arie > Kleingeld PA3A > Sent: Wednesday, April 02, 2008 6:45 PM > To: [hidden email] > Subject: [Elecraft] K3: Would not it be nice... > > > > Would not it be nice... if someone measured the IMD dynamic > range of the K3 with the interfering signals placed within > the bandwidth of the first IF (roofing) filter? Or has that > one already been published somewhere? Or is that impossible > to measure? > > Arie PA3A > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Arie Kleingeld PA3A
To answer your last question, PA3AKE has published 3rd Order Dynamic Range
data with both signals in the passband of the roofing filter of a homebrewed receiver's front end. You might like to look at his website. In my experience when working 40m SSB DX zero beat with a BC station's carrier, maintaining a large in- passband receiver dynamic range helps a lot. 73, Geoff GM4ESD Arie Kleingeld PA3A wrote on Wednesday, April 02, 2008 11:44 PM > Would not it be nice... if someone measured the IMD dynamic range of the > K3 with the interfering signals placed within the bandwidth of the first > IF (roofing) filter? > Or has that one already been published somewhere? Or is that impossible > to measure? > > Arie PA3A _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by w7go
Tony Morgan wrote:
> If you use a bright lamp over the table as I do, the glare from the foil > would not be good. > As has been said before, if you are going to spent the money on a nice > Elecraft kit, spend > a few extra bucks and get a anti static mat. > Just my opinion. Not to mention that the conductivity of the aluminum foil is so high as to actually damage the ESD sensitive parts you are trying to protect. You want a conductive mat, just not so conductive so as to discharge the charges too rapidly. Conductive ESD mats are designed with just enough conductivity to slowly discharge the static buildup without causing such high discharge currents as to damage the solid state device. The mat is then connected via a several megohm resistor to the electrical ground of the room. Wrist straps of similar conductive properties are used to ensure a common potential between your body and the bench mat. A floor mat of a similar material, and grounded as the bench mat would be (or a conductive floor surface), and either conductive shoes and socks, or special inserts with heel and body skin contact are often used where movement is necessary in a lab and a wrist strap is too restrictive. Special air ionizers, often generating the ionized stream via a radioactive polonium pellet are often used for extra protection at workstations. I think the original reference to aluminum foil was a joke, wasn't it? It was highlighted. Not everyone may have understood. Additionally, the conductive surface of the foil would be a shock hazard, also something undesirable on a workbench. Rick Kunath, k9ao _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Arie Kleingeld PA3A
For a graphic representation of Joe's point, check out the BDR section
of my LP-PAN web page at http://www.telepostinc.com/LP-PAN.html I ran some tests of the K3/LP-PAN combo for very close in interference. The phase noise issue pointed out by Joe can be seen quite easily in the panoramic display. As you slide the interfering signal toward the wanted one, the noise sidebands of the interfering signal become higher than the noise floor, and eventually louder than the desired signal. In my test, I slid a very clean S9+63dB signal from an analog HP generator toward a 3uV desired signal, and the noise sidebands were just audible at a bit over 3 kHz spacing. With the interfering signal at S9+18dB, the sidebands could be heard at about 800 Hz spacing. With this strength of interference, the interfering signal had to be within about 200 Hz to wipe out the desired signal. This would be worse with a synthesized rig as the interference, of course, or a signal with modulation (even CW). At this signal level (just below the HAGC threshold), the K3's DSP dynamic range is high enough that AGC could be disabled, avoiding pumping. It's a moot point, however, since you're not likely to find interference this clean in practice, unless your neighbor has a xtal controlled QRP rig ;-) 73, Larry N8LP > ------------------------------ > > Message: 49 > Date: Wed, 2 Apr 2008 22:29:33 -0400 > From: "Joe Subich, W4TV" <[hidden email]> > Subject: RE: [Elecraft] K3: Would not it be nice... > To: "'Arie Kleingeld PA3A'" <[hidden email]>, > <[hidden email]> > Message-ID: <007101c89532$8dd63bb0$0400000a@laptop> > Content-Type: text/plain; charset="US-ASCII" > > > Nobody makes 500 Hz IMD dynamic range measurements - they > are meaningless but that is what it would take to get both > interfering signals inside the passband of the 2.7 KHz > roofing filter. > > Sherwood has made some very close in blocking dynamic range > measurements but I do not know if he has released that data. > The essence of the private e-mail is that even at 1 KHz the > limiting factor in the K3 is not blocking but phase noise > performance of the K3 and/or the interfering signal. > > The final analysis is that key clicks and phase noise from > signals less than 1 KHz way would be more of a problem than > either IMD or blocking. > > 73, > > ... Joe, W4TV > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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> For a graphic representation of Joe's point, check out the > BDR section of my LP-PAN web page at > http://www.telepostinc.com/LP-PAN.html The 5 KHz and 2 KHz examples with LP-Pan and PowerSDR are "worst case" for the K3 and would be equivalent to using the FM filter for all modes. Even at 2 KHz, the interfering carrier would be nearly 30 dB down the skirt of the 2.8 KHz/8 pole filter and any IMD between it and another signal even farther away would be down significantly (assuming the CW signal is centered). Phase noise, key clicks and transmitted IMD from other stations will be the limiting factor for receiver performance in the K3. 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Larry Phipps > Sent: Thursday, April 03, 2008 9:15 AM > To: [hidden email] > Subject: RE: [Elecraft] K3: Would not it be nice... > > > For a graphic representation of Joe's point, check out the > BDR section > of my LP-PAN web page at http://www.telepostinc.com/LP-PAN.html > > I ran some tests of the K3/LP-PAN combo for very close in > interference. > The phase noise issue pointed out by Joe can be seen quite > easily in the > panoramic display. As you slide the interfering signal toward > the wanted > one, the noise sidebands of the interfering signal become higher than > the noise floor, and eventually louder than the desired signal. In my > test, I slid a very clean S9+63dB signal from an analog HP generator > toward a 3uV desired signal, and the noise sidebands were > just audible > at a bit over 3 kHz spacing. With the interfering signal at > S9+18dB, the > sidebands could be heard at about 800 Hz spacing. With this > strength of > interference, the interfering signal had to be within about 200 Hz to > wipe out the desired signal. This would be worse with a > synthesized rig > as the interference, of course, or a signal with modulation > (even CW). > At this signal level (just below the HAGC threshold), the K3's DSP > dynamic range is high enough that AGC could be disabled, avoiding > pumping. It's a moot point, however, since you're not likely to find > interference this clean in practice, unless your neighbor has a xtal > controlled QRP rig ;-) > > 73, > Larry N8LP > > > > > ------------------------------ > > > > Message: 49 > > Date: Wed, 2 Apr 2008 22:29:33 -0400 > > From: "Joe Subich, W4TV" <[hidden email]> > > Subject: RE: [Elecraft] K3: Would not it be nice... > > To: "'Arie Kleingeld PA3A'" <[hidden email]>, > > <[hidden email]> > > Message-ID: <007101c89532$8dd63bb0$0400000a@laptop> > > Content-Type: text/plain; charset="US-ASCII" > > > > > > Nobody makes 500 Hz IMD dynamic range measurements - they > > are meaningless but that is what it would take to get both > > interfering signals inside the passband of the 2.7 KHz > > roofing filter. > > > > Sherwood has made some very close in blocking dynamic range > > measurements but I do not know if he has released that data. > > The essence of the private e-mail is that even at 1 KHz the > > limiting factor in the K3 is not blocking but phase noise > > performance of the K3 and/or the interfering signal. > > > > The final analysis is that key clicks and phase noise from signals > > less than 1 KHz way would be more of a problem than either IMD or > > blocking. > > > > 73, > > > > ... Joe, W4TV > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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The example wasn't meant to be K3 specific, but rather to graphically
show the concept of why transmitted phase noise is such an important factor with close in interference. The overall BW in these examples is actually >192 kHz! Larry N8LP Joe Subich, W4TV wrote: >> For a graphic representation of Joe's point, check out the >> BDR section of my LP-PAN web page at >> http://www.telepostinc.com/LP-PAN.html >> > > The 5 KHz and 2 KHz examples with LP-Pan and PowerSDR are "worst > case" for the K3 and would be equivalent to using the FM filter > for all modes. Even at 2 KHz, the interfering carrier would be > nearly 30 dB down the skirt of the 2.8 KHz/8 pole filter and > any IMD between it and another signal even farther away would > be down significantly (assuming the CW signal is centered). > > Phase noise, key clicks and transmitted IMD from other stations > will be the limiting factor for receiver performance in the K3. > > 73, > > ... Joe, W4TV > > > > > > >> -----Original Message----- >> From: [hidden email] >> [mailto:[hidden email]] On Behalf Of Larry Phipps >> Sent: Thursday, April 03, 2008 9:15 AM >> To: [hidden email] >> Subject: RE: [Elecraft] K3: Would not it be nice... >> >> >> For a graphic representation of Joe's point, check out the >> BDR section >> of my LP-PAN web page at http://www.telepostinc.com/LP-PAN.html >> >> I ran some tests of the K3/LP-PAN combo for very close in >> interference. >> The phase noise issue pointed out by Joe can be seen quite >> easily in the >> panoramic display. As you slide the interfering signal toward >> the wanted >> one, the noise sidebands of the interfering signal become higher than >> the noise floor, and eventually louder than the desired signal. In my >> test, I slid a very clean S9+63dB signal from an analog HP generator >> toward a 3uV desired signal, and the noise sidebands were >> just audible >> at a bit over 3 kHz spacing. With the interfering signal at >> S9+18dB, the >> sidebands could be heard at about 800 Hz spacing. With this >> strength of >> interference, the interfering signal had to be within about 200 Hz to >> wipe out the desired signal. This would be worse with a >> synthesized rig >> as the interference, of course, or a signal with modulation >> (even CW). >> At this signal level (just below the HAGC threshold), the K3's DSP >> dynamic range is high enough that AGC could be disabled, avoiding >> pumping. It's a moot point, however, since you're not likely to find >> interference this clean in practice, unless your neighbor has a xtal >> controlled QRP rig ;-) >> >> 73, >> Larry N8LP >> >> >> >> >>> ------------------------------ >>> >>> Message: 49 >>> Date: Wed, 2 Apr 2008 22:29:33 -0400 >>> From: "Joe Subich, W4TV" <[hidden email]> >>> Subject: RE: [Elecraft] K3: Would not it be nice... >>> To: "'Arie Kleingeld PA3A'" <[hidden email]>, >>> <[hidden email]> >>> Message-ID: <007101c89532$8dd63bb0$0400000a@laptop> >>> Content-Type: text/plain; charset="US-ASCII" >>> >>> >>> Nobody makes 500 Hz IMD dynamic range measurements - they >>> are meaningless but that is what it would take to get both >>> interfering signals inside the passband of the 2.7 KHz >>> roofing filter. >>> >>> Sherwood has made some very close in blocking dynamic range >>> measurements but I do not know if he has released that data. >>> The essence of the private e-mail is that even at 1 KHz the >>> limiting factor in the K3 is not blocking but phase noise >>> performance of the K3 and/or the interfering signal. >>> >>> The final analysis is that key clicks and phase noise from signals >>> less than 1 KHz way would be more of a problem than either IMD or >>> blocking. >>> >>> 73, >>> >>> ... Joe, W4TV >>> >>> >> _______________________________________________ >> Elecraft mailing list >> Post to: [hidden email] >> You must be a subscriber to post to the list. >> Subscriber Info (Addr. Change, sub, unsub etc.): >> http://mailman.qth.net/mailman/listinfo/elecraft >> >> Help: http://mailman.qth.net/subscribers.htm >> Elecraft web page: http://www.elecraft.com >> > > > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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