Re: Topband: Problem with compression F connectors on Quad RG-6
CATV installers use almost 100% quad shield in order to keep the signals inside and not cause interfering leakage (egress); FCC specs are adamant about that. These specs go back to the 70's. In more recent years the cable also must keep local RFI (ingress) out. While they do use tape foil shield cables, CATV systems rarely use quad shield cables. As a matter of fact I just bought a bunch of drop cable from a CATV system, and it is all single foil single braid. This is true for the drop, which has a messenger strand, and the house wiring, which is identical without a messenger strand. In the late 70's and early 80's, I was system's engineer at a company that had dozens of small cable systems. We inherited some systems near an FM/AM station that had a second harmonic on a local TV channel video frequency. The former cable system operator had given up, after installing quad shield and all sorts of special cables. 100% of their problems were isolated power and CATV grounds, letting the AM signal loop through the system, and the quad shield developing poor connections letting the FM harmonic in. We ripped all that stuff out, and went with normal hardline and good quality drop cable, bonded the cable grounds to the entrance and breaker panels, and nearly 100% cured the system. We had dumpster load of special cable that was nothing but connector headaches. The standard drop cable is a bonded foil with single braid, it has been that way since the late 1970's. The current best grade is Brightwire by CommScope. Any good cable will far exceed FCC specs without a quad shield. Single-foil single-shield Brightwire has over 120 dB of external shield current to center conductor current isolation on 160 meters, and it gets better as you go up in frequency. I can't imagine anyone needing more than 80 dB isolation outside the house, and maybe 100 dB if it is in a noisy house. All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
What role does skin effect have in this situation - at 1.8 MHz? Skin depth isolates the outside and inside, virtually nothing passes through a conductor wall that is several skin depths thick. This is true for both the magnetic field and the electric field, and why shielded loops are a misnomer. Look at this link http://www.w8ji.com/skindepth.htm Current in the center has to be matched by current on the inside of the closest shield. Current always can get into the center three ways: 1.) The shield can be so thin it doesn't isolate the outside and inside, but then that would not be a good shield 2.) Current spills over an edge 3.) There is a direct connection to the inside If we study connectors with an accurate picture of what current has to do (current, the magnetic field, nor the electric field can NOT go through a wall several skin depths thick), we can spot potential issues with shield connections. We don't have to have a connection to the side if there is an edge to spill over that is right at the same connection spot. What we do not want is the edge to be inches from the connection point. For example, a braid overlay on top of foil that has a poor electrical and pressure connection to the foil is not a good connection point. This is why LMR400 is problematic when the braid is soldered to a PL-259. The very same cable is great with a crimp connector, if the cable is clean (not tarnished or corroded) inside. 73 Tom All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
The standard drop cable is a bonded foil with single braid, it has been that way since the late 1970's. The current best grade is Brightwire by CommScope. Any good cable will far exceed FCC specs without a quad shield. It remained that way with Comcast ATT Broadband at least until 2002 when I left ATT corporate engineering, shortly after the merger. I doubt much has changed since then. Concerns are a bit different in the broadband world where downstream leakage must be minimized between 50 MHz - 1 GHz. The upstream path is in HF region, but no sane cable operator uses spectrum below about 10 MHz. The only services anywhere near that area of spectrum are used for data transponders and IPPV from the set-top box where modulation is almost always QPSK. Telephony and DOCSIS cable modem service is all relegated to an area above 20 MHz. In the Jacksonville Comcast system, it's now all above 30 MHz which was made possible through the use of tighter diplexer specs in the system amps and fiber-optic nodes. if you could see a spectrum analyzer display of the return path back at the headend, you would be amazed that the return path works at all. Any point of ingress results high levels of interference, most notably SWBC. I recall writing up a paper in the mid-'90s that predicted a need for better return path certification and an upward move of the lowest usable frequency to well above 20 MHz. I pointed to the 11-year sunspot cycle as an important driver. The non-ham engineers in our group didn't get it. But the CTO of MediaOne was a ham, and he did get it. The public did not know it, but there was a real fear between 1995 and 2000 that return path broadband technology would never work. When you consider all the points of potential failure, especially on a power-passing system, it truly is a miracle that it works at all. Consider this: The typical fiber-optic node services between 200-500 home passings. From the comfort of your living room, and with an RF signal generator, one can wipe out an entire service area when the return path frequencies of the system are known. This isn't theoretical, I demonstrated the impact to a sober group of engineers with an Eico generator. That potential still exists today. Concerning SANS connectors and wiring, I would take the lead from the cable operators. They cannot afford to have unreliable cables anywhere between the customer equipment and the headend or hub facilities. When you've got thousands of miles of cable plant and interfacing hardware, that becomes the most important piece in the network. If a router, modulator or fiber amp fails in the system, the fix is easy with money. But if you deploy bad cable and hardware into a system, you'll feel the pain a long time as it affects long-term service call volume, unhappy customers, and angry government leaders who generally hate the cable operators. Paul, W9AC All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Topband: fine whiskey is a daylight beverage
fine whiskey is a daylight beverage is appended to the end of each posting. At first I thought it was the personal signature file of the individual poster but it is on everyone's posting. It was kind of cute the first time I saw it But ok, I get the point. How about replacing it with (could rotate messages periodically) - Big antennas work better DX is better after midnight More watts equals more S/N QRP is for 10 meters or my favorite ... Rick K2XT All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: fine whiskey is a daylight beverage
How about, QRP is a challenge - be challenged From one of a few who LOVEs working QRP on 160 and 80 meters! 72, Jim Rodenkirch, K9JWV From: rstea...@hotmail.com To: topband@contesting.com Date: Tue, 7 May 2013 14:55:49 + Subject: Topband: fine whiskey is a daylight beverage fine whiskey is a daylight beverage is appended to the end of each posting. At first I thought it was the personal signature file of the individual poster but it is on everyone's posting. It was kind of cute the first time I saw it But ok, I get the point. How about replacing it with (could rotate messages periodically) - Big antennas work better DX is better after midnight More watts equals more S/N QRP is for 10 meters or my favorite ... Rick K2XT All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
Improper connector installation plagues many ham stations, not only with RG-6 CATV connectors but with all types of coaxial connectors. An improperly installed connector is an invitation to RFI ingress and equipment damage. At transmit power levels, an improperly installed connector can cause equipment damage. If you're not confident in your connector installation skills, its worth a few dollars to have them professionally installed. Quad cable connector installation requires skills and patience. Compounding the problem, hams often use connectors that are not intended for use with quad RG-6. Quad cable connector installation involves five specific steps, each performed carefully and correctly: 1. Use an RG-6 stripping tool to remove the jacket. Inspect the braid wires to be sure none of the wires are damaged. Never use a knife to remove the jacket, inevitably it will damage the fragile braid wires no matter how careful you are. 2. Carefully fold back only the outer braid and spread the braid wires evenly around the circumference of the cable jacket. Verify that no wires are broken. All of the braid wires should lay flat over the jacket, should not be more than 1/4 inch long, and should not be bunched up. 3. Remove the foil tape between the two braid shields. Do not use a knife to assist in foil tape removal. This step is time consuming and often ignored. The connector will be very difficult to install if the foil tape is not removed. If somehow you manage to force the connector onto the cable with the foil tape in place, the connector will be intermittent and unreliable. 4. Carefully fold back the inner braid and spread the braid wires evenly around the circumference of the cable jacket. Verify that no wires are broken. All of the braid wires should lay flat over the jacket, should not be more than 1/4 inch long, and should not be bunched up. 5. Install the proper connector for quad shield cable. Be sure the connector is fully seated. If you need to use great force to mate the connector something is wrong, either you used the wrong connector or the cable was improperly prepared . If somehow you manage to force the connector onto the cable, the connector will be intermittent and unreliable. Improper connector installation is so pervasive in the cable TV industry that CommScope prepared an illustrated paper on improper connector installation. http://docs.commscope.com/Public/ImproperQuadPrep.pdf 73 Frank W3LPL - Original Message - From: Paul Christensen w...@arrl.net To: topband topband@contesting.com Sent: Tuesday, May 7, 2013 3:33:00 PM Subject: Re: Topband: Problem with compression F connectors on Quad RG-6 The standard drop cable is a bonded foil with single braid, it has been that way since the late 1970's. The current best grade is Brightwire by CommScope. Any good cable will far exceed FCC specs without a quad shield. It remained that way with Comcast ATT Broadband at least until 2002 when I left ATT corporate engineering, shortly after the merger. I doubt much has changed since then. Concerns are a bit different in the broadband world where downstream leakage must be minimized between 50 MHz - 1 GHz. The upstream path is in HF region, but no sane cable operator uses spectrum below about 10 MHz. The only services anywhere near that area of spectrum are used for data transponders and IPPV from the set-top box where modulation is almost always QPSK. Telephony and DOCSIS cable modem service is all relegated to an area above 20 MHz. In the Jacksonville Comcast system, it's now all above 30 MHz which was made possible through the use of tighter diplexer specs in the system amps and fiber-optic nodes. if you could see a spectrum analyzer display of the return path back at the headend, you would be amazed that the return path works at all. Any point of ingress results high levels of interference, most notably SWBC. I recall writing up a paper in the mid-'90s that predicted a need for better return path certification and an upward move of the lowest usable frequency to well above 20 MHz. I pointed to the 11-year sunspot cycle as an important driver. The non-ham engineers in our group didn't get it. But the CTO of MediaOne was a ham, and he did get it. The public did not know it, but there was a real fear between 1995 and 2000 that return path broadband technology would never work. When you consider all the points of potential failure, especially on a power-passing system, it truly is a miracle that it works at all. Consider this: The typical fiber-optic node services between 200-500 home passings. From the comfort of your living room, and with an RF signal generator, one can wipe out an entire service area when the return path frequencies of the system are known. This isn't theoretical, I demonstrated the impact to a sober group of engineers with an Eico generator. That potential still
Re: Topband: fine whiskey is a daylight beverage
How about replacing it with nothing! I find the current one offensive and dont think any forced signature is warranted. Carl KM1H - Original Message - From: Rick Stealey rstea...@hotmail.com To: topband@contesting.com Sent: Tuesday, May 07, 2013 10:55 AM Subject: Topband: fine whiskey is a daylight beverage fine whiskey is a daylight beverage is appended to the end of each posting. At first I thought it was the personal signature file of the individual poster but it is on everyone's posting. It was kind of cute the first time I saw it But ok, I get the point. How about replacing it with (could rotate messages periodically) - Big antennas work better DX is better after midnight More watts equals more S/N QRP is for 10 meters or my favorite ... Rick K2XT All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3162/5805 - Release Date: 05/07/13 All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Topband: 'Re: fine whiskey is a daylight beverage
offensive? How about Tuesday? Is THAT offensive too? sheesh! -- Original Message -- From: ZR z...@jeremy.mv.com To: Rick Stealey rstea...@hotmail.com, topband@contesting.com Subject: Re: Topband: fine whiskey is a daylight beverage Date: Tue, 7 May 2013 12:24:29 -0400 How about replacing it with nothing! I find the current one offensive and dont think any forced signature is warranted. Carl KM1H - Original Message - From: Rick Stealey rstea...@hotmail.com To: topband@contesting.com Sent: Tuesday, May 07, 2013 10:55 AM Subject: Topband: fine whiskey is a daylight beverage fine whiskey is a daylight beverage is appended to the end of each posting. At first I thought it was the personal signature file of the individual poster but it is on everyone's posting. It was kind of cute the first time I saw it But ok, I get the point. How about replacing it with (could rotate messages periodically) - Big antennas work better DX is better after midnight More watts equals more S/N QRP is for 10 meters or my favorite ... Rick K2XT All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3162/5805 - Release Date: 05/07/13 All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector Woman is 60 But Looks 25 Mom publishes simple facelift trick that angered doctors... http://thirdpartyoffers.juno.com/TGL3131/51893ba11c67d3ba1293ast03duc All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: 'Re: fine whiskey is a daylight beverage
On 2013-05-07, at 1:35 PM, n...@juno.com wrote: offensive? How about Tuesday? Is THAT offensive too? sheesh! How about replacing it with nothing! I find the current one offensive and dont think any forced signature is warranted. Oh PLEASE let's leave all of the PC BS OFF of this Reflector, just have a bit of fun, OK...?! ~73~ de Eddy VE3CUI - VE3XZ All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: More fishing beacons on 160
2013 Additions (fishbeacons) include: 1801 OJ7E 1806 HV8E 1811 GX3E 1823 ZM4 1826 GX8E 1828 WK4 1832 MB1E 1836 NM7E thank you for the addition of NR3E and ADU1, duly noted. I will try to remember to bring an up-to-date listing to Dayton. ANYONE WHO HAS ADDITIONS TO THE LISTING ***PLEASE*** TELL US NOW -- Original Message -- From: Mike Waters mikew...@gmail.com To: topband topband@contesting.com Subject: Topband: More fishing beacons on 160 Date: Mon, 6 May 2013 22:02:43 -0500 I can't believe this. More fishnet beacons intruding on 160! I heard this one way before sunset. Call Freq NR3E 1.868 ADU1 1.910 Somebody please remind me where the page listing of 160 fishnet beacons is. 73, Mike www.w0btu.com All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector BlackBerry#174 10 Get the latest details on the new BlackBerry 10 smartphone. http://thirdpartyoffers.juno.com/TGL3131/51893eba60fac3eba620ast01duc All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: fine whiskey is a daylight beverage (James Rodenkirch)
A wise old low band ham once told me QRP awards should be given to the poor basturds on the receiving end. How about, QRP is a challenge - be challenged From one of a few who LOVEs working QRP on 160 and 80 meters! 72, Jim Rodenkirch, K9JWV From: rstea...@hotmail.com To: topband@contesting.com Date: Tue, 7 May 2013 14:55:49 + Subject: Topband: fine whiskey is a daylight beverage fine whiskey is a daylight beverage is appended to the end of each posting. At first I thought it was the personal signature file of the individual poster but it is on everyone's posting. It was kind of cute the first time I saw it But ok, I get the point. How about replacing it with (could rotate messages periodically) - Big antennas work better DX is better after midnight More watts equals more S/N QRP is for 10 meters or my favorite ... Rick K2XT All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
- Original Message - From: Tom W8JI w...@w8ji.com To: topband topband@contesting.com Sent: Tuesday, May 07, 2013 9:48 AM Subject: Re: Topband: Problem with compression F connectors on Quad RG-6 CATV installers use almost 100% quad shield in order to keep the signals inside and not cause interfering leakage (egress); FCC specs are adamant about that. These specs go back to the 70's. In more recent years the cable also must keep local RFI (ingress) out. While they do use tape foil shield cables, CATV systems rarely use quad shield cables. As a matter of fact I just bought a bunch of drop cable from a CATV system, and it is all single foil single braid. This is true for the drop, which has a messenger strand, and the house wiring, which is identical without a messenger strand. In the late 70's and early 80's, I was system's engineer at a company that had dozens of small cable systems. We inherited some systems near an FM/AM station that had a second harmonic on a local TV channel video frequency. The former cable system operator had given up, after installing quad shield and all sorts of special cables. 100% of their problems were isolated power and CATV grounds, letting the AM signal loop through the system, and the quad shield developing poor connections letting the FM harmonic in. We ripped all that stuff out, and went with normal hardline and good quality drop cable, bonded the cable grounds to the entrance and breaker panels, and nearly 100% cured the system. We had dumpster load of special cable that was nothing but connector headaches. The standard drop cable is a bonded foil with single braid, it has been that way since the late 1970's. The current best grade is Brightwire by CommScope. Any good cable will far exceed FCC specs without a quad shield. Single-foil single-shield Brightwire has over 120 dB of external shield current to center conductor current isolation on 160 meters, and it gets better as you go up in frequency. I can't imagine anyone needing more than 80 dB isolation outside the house, and maybe 100 dB if it is in a noisy house. Around here Comcast installers use TFC T-10 quad shield. Ive also seen PPC trishield used for satellite. As you can easily see they list their cables by RF noise enviroment from low for standard dual shield, medium-moderate for premium dual shield, plus high for trishield and quad for severe with these last 2 also rated for 2 way use. http://www.timesfiber.com/TFC_Cable_Book_III.pdf Go to Page 36 Dont let ANYONE tell you that the shielding type isnt important. In the 80's I was an engineering manager for Wang Labs broadband networking RD department and one of my responsibilities was qualifying all cable related components for outdoor and indoor use for moderate to severe RF enviroments which included nuclear carriers and plants, plus oil refineries. There was a measurable difference between dual and quad shield as well as percent of braid coverage. These cables plus connectors were tested in the screen room in the Tempest group. Tempest was a DOD/CIA Top Secret program tasked to minimize electronic signal ingress and egress from spies and saboteurs. Since I had maintained my TS Crypto clearance as a USN Reservist and as an engineering tech and an engineer for Sanders Associates who was a leader in Tempest technology, I had full access to the testing. I have also applied that knowledge at home for ham and consumer products ever since. It was Tempest starting in the mid 70's that gave me an understanding of ferrites for RFI, etc and that was applied to Wangs network as well as at home where I continue to do mortal battle with noise generators and common mode. Carl KM1H All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
But if you deploy bad cable and hardware into a system, you'll feel the pain a long time as it affects long-term service call volume, unhappy customers, and angry government leaders who generally hate the cable operators. Paul, W9AC I started the Cable Committee here and led it thru many negotiations and problems with various CATV outfits over 25 years. The current group along with Comcast have maintained an excellent relationship but it took lots of training of committee members who did not have a tech backround and beating on cable company reps who would try anything to claim innocence or double talk their way around contract, and technical issues (much like what happens on some ham forums (-; It was a nice compliment when other towns sent their members here to get edumecated. Carl KM1H All good topband ops know fine whiskey is a daylight beverage. _ Topband Reflector
Re: Topband: Wall warts
This has nothing to do with wall warts. I am just testing to see where that fine whiskey signature is coming from. - Wes Attaway (N5WA) --- 1138 Waters Edge Circle, Shreveport, LA 71106 318-797-4972 (Office) - 318-393-3289 (Cell) Computer Consulting and Forensics -- EnCase Certified Examiner --- All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: Wall warts
The fine whiskey signature has been there for a long time. I am surprised this has become an issue. It was suggested by one of the members of this list and I thought it was funny and appropriate and not the least bit offensive., I have changed it now to something that uses many of the same words - but hopefully is not the least bit offensive to anyone. Tree On Tue, May 7, 2013 at 12:17 PM, Wes Attaway (N5WA) wesatta...@bellsouth.net wrote: This has nothing to do with wall warts. I am just testing to see where that fine whiskey signature is coming from. - Wes Attaway (N5WA) --- 1138 Waters Edge Circle, Shreveport, LA 71106 318-797-4972 (Office) - 318-393-3289 (Cell) Computer Consulting and Forensics -- EnCase Certified Examiner --- All good topband ops know how to put up a beverage at night. _ Topband Reflector All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: Wall warts
The fine whiskey signature has been there for a long time. I am surprised this has become an issue. I started the whole thing, not trying to make it an issue, but mostly I was confused when I first saw it because I thought it was a personal signature file, then saw everyone was using it ! Then finally realized it was done by the server. Actually it was rather clever, so is the beverage one (till you've seen it 1000 times !) Rick K2XT All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: 'Re: fine whiskey is a daylight beverage
I suppose that We do it in the dark wouldn't go over very well, right? 73, Jim N7US -Original Message- offensive? How about Tuesday? Is THAT offensive too? sheesh! -- Original Message -- How about replacing it with nothing! I find the current one offensive and dont think any forced signature is warranted. Carl KM1H All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: Wall warts
down the street where i live i have several clandestine copper pipes driven into the ground in neighbor's front yards for nighttime beverages and a spool of wire mounted on my bicycle, wound back up with my screw gun in the early morning.. thank god i have retired from contesting mike w7dra All good topband ops know how to put up a beverage at night. _ Topband Reflector Political system upset? Democrats BIG advantage in America about to completely vanish http://thirdpartyoffers.juno.com/TGL3141/518972f52305572f41ab3st01vuc All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
On 5/7/2013 9:23 AM, donov...@starpower.net wrote: 3. Remove the foil tape between the two braid shields. Do not use a knife to assist in foil tape removal. This step is time consuming and often ignored. The connector will be very difficult to install if the foil tape is not removed. If somehow you manage to force the connector onto the cable with the foil tape in place, the connector will be intermittent and unreliable. This is the key issue with these things. I find that I simply cannot tear the foil with my bare hands, on account of the fact that it is not foil, but rather plastic (probably mylar) with an evaporated or sputtered metal coating. I have resorted to using a very small pair of diagonal cutters to cut the foil. Any other suggestions? Rick N6RK All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
You've been watching over my shoulder, Rick. Mis dos centavos de Milt, N5IA -Original Message- From: Richard (Rick) Karlquist Sent: Tuesday, May 07, 2013 3:27 PM To: donov...@starpower.net Cc: PVRC ; topband Subject: Re: Topband: Problem with compression F connectors on Quad RG-6 On 5/7/2013 9:23 AM, donov...@starpower.net wrote: 3. Remove the foil tape between the two braid shields. Do not use a knife to assist in foil tape removal. This step is time consuming and often ignored. The connector will be very difficult to install if the foil tape is not removed. If somehow you manage to force the connector onto the cable with the foil tape in place, the connector will be intermittent and unreliable. This is the key issue with these things. I find that I simply cannot tear the foil with my bare hands, on account of the fact that it is not foil, but rather plastic (probably mylar) with an evaporated or sputtered metal coating. I have resorted to using a very small pair of diagonal cutters to cut the foil. Any other suggestions? Rick N6RK All good topband ops know how to put up a beverage at night. _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.3272 / Virus Database: 3162/6306 - Release Date: 05/07/13 All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
The way that you are doing it it exactly the way that Belden recommends doing it in their 3' 37 video on YouTube (the video recommended here on May 5 by Paul, W9AC). I forget the exact URL, but it's easy to find. Belden has several similar videos on YouTube for other types of coax and connectors; the video you want is the one that's 3' 37 long. That foil with the blue Mylar coating between the braids HAS to be removed. The other foil, the one that's bonded to the outside of the dielectric, is NOT removed. 73, Mike www.w0btu.com On Tue, May 7, 2013 at 5:27 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: 3. Remove the foil tape between the two braid shields. Do not use a knife to assist in foil tape removal. This step is time consuming and often ignored. ... This is the key issue with these things. I find that I simply cannot tear the foil with my bare hands, on account of the fact that it is not foil, but rather plastic (probably mylar) with an evaporated or sputtered metal coating. I have resorted to using a very small pair of diagonal cutters to cut the foil. Any other suggestions? All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: More fishing beacons on 160
I forgot to mention the direction: Southeast. I heard this beacon very well when the sun was still way above the horizon here. It must be running a lot of power, if it's in the Gulf of Mexico. 73, Mike www.w0btu.com On Mon, May 6, 2013 at 10:02 PM, Mike Waters mikew...@gmail.com wrote: I can't believe this. More fishnet beacons intruding on 160! I heard this one way before sunset. Call Freq NR3E 1.868 ADU1 1.910 Somebody please remind me where the web page listing 160 fishnet beacons is. All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: Wall warts
- Original Message - I dont care for forced signatures...period. Just more useless bandwidth to be erased when replying so as to not aggravate you with untrimmed messages. Carl The fine whiskey signature has been there for a long time. I am surprised this has become an issue. It was suggested by one of the members of this list and I thought it was funny and appropriate and not the least bit offensive., I have changed it now to something that uses many of the same words - but hopefully is not the least bit offensive to anyone. Tree On Tue, May 7, 2013 at 12:17 PM, Wes Attaway (N5WA) wesatta...@bellsouth.net wrote: This has nothing to do with wall warts. I am just testing to see where that fine whiskey signature is coming from. - Wes Attaway (N5WA) --- 1138 Waters Edge Circle, Shreveport, LA 71106 318-797-4972 (Office) - 318-393-3289 (Cell) Computer Consulting and Forensics -- EnCase Certified Examiner --- All good topband ops know how to put up a beverage at night. _ Topband Reflector All good topband ops know how to put up a beverage at night. _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1432 / Virus Database: 3162/5805 - Release Date: 05/07/13 All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
This is the YouTube video Mike referred to: https://www.youtube.com/watch?v=kN1yUBp2CzI 73 Frank W3LPL - Original Message - From: Mike Waters mikew...@gmail.com To: topband topband@contesting.com Sent: Tuesday, May 7, 2013 11:49:06 PM Subject: Re: Topband: Problem with compression F connectors on Quad RG-6 The way that you are doing it it exactly the way that Belden recommends doing it in their 3' 37 video on YouTube (the video recommended here on May 5 by Paul, W9AC). I forget the exact URL, but it's easy to find. Belden has several similar videos on YouTube for other types of coax and connectors; the video you want is the one that's 3' 37 long. That foil with the blue Mylar coating between the braids HAS to be removed. The other foil, the one that's bonded to the outside of the dielectric, is NOT removed. 73, Mike www.w0btu.com On Tue, May 7, 2013 at 5:27 PM, Richard (Rick) Karlquist rich...@karlquist.com wrote: 3. Remove the foil tape between the two braid shields. Do not use a knife to assist in foil tape removal. This step is time consuming and often ignored. ... This is the key issue with these things. I find that I simply cannot tear the foil with my bare hands, on account of the fact that it is not foil, but rather plastic (probably mylar) with an evaporated or sputtered metal coating. I have resorted to using a very small pair of diagonal cutters to cut the foil. Any other suggestions? All good topband ops know how to put up a beverage at night. _ Topband Reflector All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: fine whiskey is a daylight beverage
Never go to excess, but let moderation be your guide All good topband ops know how to put up a beverage at night. _ Topband Reflector
Re: Topband: Problem with compression F connectors on Quad RG-6
I'm interested in your comment about LMR400 and soldered braids, Tom. I understand the point about shield current flowing on the insde of the foil or braid closest to the center conductor, but if the shield connection is faulty, oxidized, or has high resistance, then it seems to me the outer braid (presumed to be soldered to the PL259) would carry a potion of the return current. It would be an interesting physics problem to work out the relative return currents carried by a coaxial cable with two concentric shields, each having non-zero resistivity, or a thickness comparable or thinner than the skin depth.. I don't recall the skin depth at 1.8MHz, but my guess is it's probably longer than the thickness of the coating on aluminized mylar. I don't know what the foil thickness is on LMR400. 2 MHz skin depth of copper is .0018 inches. 2 MHz skin depth of aluminum is .0023 inches. The LMR400 type cable I have is about .006-.008 foil. I chemically stripped the foil off, and the foil was two wraps thick around the cable. LMR400 or any cable, in sensitive applications, requires a solid bond to the shield that carries the vast majority of return current. In the case of almost all cables on HF and higher, that is the innermost foil. Of course it is different at audio or lower frequencies. One common connector problem comes from not forcing the woven shield tight against the foil at the connector, or having the foil or woven shield tarnish or corrode. The path to the inside of the foil is out on the braid to an eventual contact point, then back on the outside of the foil to the foil edge. At the edge current can go inside. This is like adding 2X the length of the path to the connection point in overall shield connection path length. (Current can also get in across the edge of a longitudinal seam, if the seam's overlap is insulated. The problem with that is the seam can kill UHF performance.) If you solder to the shield of LMR400, and put it on a network analyzer and measure the stub characteristics, many times (not always) it will move around as the cable is flexed. This is because the soldering heat contracts the dielectric, releasing pressure between the braid overlay and the foil. Now you have a crummy connection that changes electrical length of the connection to the real shield. Even if you do things right, once the foil and braid develop an oxide layer the connection goes away. This can work its way out for several feet of cable length, really messing up a cable. This will not show with a single shield. Cables with foil have to be installed and treated correctly. The more layers you add, the more careful we must be. Since the extra layers are pretty much meaningless, the best practice is to avoid them. Use a good shield against the center and connect to it at the connector. I also wonder about the ability of a thin foil shield to carry Amps of RF without appreciable loss! RF flows on the surfaces nearest opposing (differential) current flow. You have the small outer surface area of the center conductor carrying the same current as all of that wide area of the foil. The shield has a great deal of surface area compared to the center. 73 Tom All good topband ops know how to put up a beverage at night. _ Topband Reflector
