Re: Topband: Stainless Steel for coil taps.
I agree Rick.. Too “clever” but just enough to fool me.. once. After I get the new coil ready (Using brass hardware to replace the stainless bolts also) and find the sweet spot again using the proper coil clips, I will SOLDER the clips onto the copper at that time without shorting out any other coil turns. Since this is a series coil at the base, I will use a shunt coil to match the swr.. I hope that is what I am going to do and not blow up something else . From: Richard (Rick) Karlquist Sent: Monday, November 16, 2020 10:02 AM To: Tim Shoppa; Larry-k1uo Cc: topband@contesting.com Subject: Re: Topband: Stainless Steel for coil taps. I _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Stainless Steel for coil taps.
@Tim, For the sake of my “experiment” I was indeed using the band clamp to hold a small aluminum eyelet soldered onto#14 wire for the tap wire. The wire used for the coil is solid copper 10 gauge wire. I found some clips that would work up to #10 wire at DX engineering called coil clips if you are looking. I believe after I rebuild a coil and tap it “properly” that things will indeed work ok. Not top dog ok but Home Owners Association ok. Thanks all for both private and public help with suggestions and helpful information for this old guy… aren’t we all. From: Tim Shoppa Sent: Monday, November 16, 2020 9:25 AM To: Larry-k1uo Cc: topband@contesting.com Subject: Re: Topband: Stainless Steel for coil taps. Conductivity of Copper: 5.85 x 10^7 mho/m Conductivity of 301 Stainless: 0.14 x 10^ mho/m Stainless is 42 times worse conductor than copper. Larry, was the band clamp holding a copper conductor onto the coil, or was the band clamp actually being relied on for conductivity. If current was being carried by the hose clamp: Typical 301 stainless band clamp (say one that will accomodate both 1/2" and 3/4" tubing) is .023" thick by 5/16" wide. For an area of 0.007 square inches carrying the current. Because copper is 42 times better conductor, a equivalent copper conductor would be just a little more than 0.00017 square inches. So that stainless band clamp is a worse conductor than AWG 26 copper wire. The tables list 26AWG as having an ampacity of 0.36A. So even at 100W and 50 ohms you are past the limit. Go to legal limit and 50 ohms and you are way past. Go to a high Q circuit and you are way way past. I would recommend something different for coil tapping for a 10AWG coil: I am a big fan of the Mueller BU-27C copper clip, rated for 40A DC. If you are going onto thick copper tubing, Mueller the BU-27CGW (the "geophone clip") works well. Tim N3QE On Sun, Nov 15, 2020 at 6:40 PM Larry-k1uo wrote: Probably everyone but me knew or knows this but it seems it is NOT a good idea to use stainless steel band clamps as coil taps. Especially on a large 160M Base coil. Oh well…. The ss band only got red hot and caused the #10 wire coils underneath it to melt into the pvc form and did not start a fire at least. Regards Larry K1UO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Stainless Steel for coil taps.
I found some small aluminum coil taps at DX Engineering I will try on the #10 solid copper coil wire I am using so as not to short multiple turns this time. The ss band clamp thing I saw on uTube (lol) but obviously he was not running 1500 watts and, with me not having tried to load an 80M vertical for 160 before, I bought it hook, line and sinker. At 72 I hate asking for help. The schedule 40 pvc form is 3.5 in OD with 35 turns of #10 wire spaced ¼ in so 4 turns per inch. I assume because the Band clamp was shoring multiple turns was what started the heating process early? I don’t know for sure but I am winding another coil as I had the machine shop make me an extra form. I terminate the #10 solid copper wire at each end of the form with a 1/1 inch stainless bolt. Hopefully I am on the right track to get back on 160M with something that the HOA wont ban me for. Thanks to all. Larry K1UO From: Roy Morgan Sent: Sunday, November 15, 2020 10:16 PM To: Larry-k1uo Cc: topband@contesting.com Subject: Re: Topband: Stainless Steel for coil taps. L _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Stainless Steel for coil taps.
Probably everyone but me knew or knows this but it seems it is NOT a good idea to use stainless steel band clamps as coil taps. Especially on a large 160M Base coil. Oh well…. The ss band only got red hot and caused the #10 wire coils underneath it to melt into the pvc form and did not start a fire at least. Regards Larry K1UO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: DX Propagation long path is getting strong this season
A couple of us in Maine also worked Joe WL7E this morning but the LP direction was closed for us. Instead, Joe was worked via the conventional NW path for me with the HI-Z array. There was some slight copy to the West direction but I attribute that to pattern overlap on the vertical RX array. So far this season we here in the NE area have had very limited and short openings of any kind to the SSW or even the SSE LP to Asia at our SS. _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Ethernet control switching of HI-Z 4-8 Pro System
Is anyone on here controlling their HI-Z 4-8 Pro (or similar) remotely over an Ethernet or VPN connection? If so, what equipment are you utilizing to do this? I am trying to eliminate controlling remotely via a USB connection at the remote location PC using Teamviewer. Thanks for any suggestions Larry K1UO _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: K3 Noise Blanker problem?
Hello all..This AM on 160 meters there was a station CQing on 1.820.6 with a fundamental freq signal strength of S9 on my K3. I also found (with the NB on) that I could hear him Q5 but very weak on 1.810.6 and the same S 0 reading but perfectly Q5 on 1.830.6. I turned the noise blanker off and of course the images disappeared. Is this a know problem when using the NB or is this just with my radio after a recent factory alignment? I have had a K3 for years and never noticed anything like that before but then again this AM was very quiet on 160M and I had the NB on because I could hear a distant tick tick of an electric fence. _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Proposal for Modification of DXCC Rules
Larry, As has been noted... worth a look and invokes serious thought on how to administer DXCC and other Awards within a constantly evolving Radio environment. DISCLAIMER:I guess since I'm currently building a remote site to continue my Ham activities/interests from this HOA I probably fall in under proposal #2. You proposal seems like a fair one to me, but then again, even though we have moved 3 times in the past 10 years, the distance involved for me has been less than 10 miles. Hardly worth arguing about my DXCC credits . -Original Message- From: Larry Burke Sent: Wednesday, February 04, 2015 2:50 PM To: topband@contesting.com Subject: Topband: Proposal for Modification of DXCC Rules A few days ago someone on the reflector suggested if you don't like the DXCC rules get them changed. Here's a proposal designed to maintain a certain amount of integrity in the DXCC program while allowing for the use of remotes, both personal and commercial. This should help those in HOA-restricted communities, those whose careers require frequent moves/travel and, in some cases, advance technical knowledge of the licensee -- all the arguments one hears defending the use of remotes. Back when the DXCC rules were changed to eliminate the requirement that all contacts must be made from within a 150 (?) mile radius to all contacts must be made from within the same entity the hobby was in a much different place. The changes were made, in part, to accommodate an increasingly mobile workforce who wanted to maintain their DXCC totals. Today, one can access personal or commercial remotes from anywhere in the world. Here's the proposal: 1. Grandfather all credits to-date -- whether they were obtained from one location, moving all over a given DXCC entity or via any type of remote 2. Revert back to DXCC being determined by station location, not the operator. To allow for local moves establish a 150 mile radius within which the station location may be moved. 3. Each operator gets to pick ONE location from which he may feed his DXCC award going forward. This can be a traditional home station, his personal remote station, or a commercial remote. But pick ONE and stick with it. No more clicking from one coast to another. Sure, there will be questions on enforceability -- but you have that now with excessive power, the all equipment within 300 meters rule, and so on. If this is a really big deal to someone, establish a DXCC OO position and scatter them around the world (like that would be a fun job!). Gotta move to a new QTH across the country and don't want to start over? -- establish a remote within 150 miles of your current location, or set one up at the local radio club for members to use. This might even encourage RHR to put remotes in all metro areas to accommodate such moves. Win-win for everyone. In the interest of transparency, if you want to weigh in on this discussion, please indicate your affiliation with any commercial remote business and/or your use/non-use of remotes to feed your awards today. Larry K5RK _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Top Loading wires
Could someone tell me the length of top loading wires (4 wires planned) needed to add to the top of a base insulated 90 foot Rohn 25g tower to maximize the radiation resistance on 160 meters. I understand there is a point of diminishing returns on the top loading lengths. The 4 wire angles will be around 45 degrees or as close as possible.If I knew how to model ,or even had a modeling program, I would attempt this already relatively simple task to many. From 50+ years of practical experience, I am ‘guessing’ maybe 28 feet long each? _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Possible abuse of call
Hi all, It has been reported to me that my call was heard during the SP test... however, as much as I would have loved to participate, I was NOT on and currently have no 160m antenna. So if K1UO managed to work you it was not from here in FN54. unless I was just ‘calling blind’. Regards to all Larry – K1UO _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Feeding a Base Insulated Tower
I have a couple questions I have never been able to find any direct answer for... so... out of curiosity... 1: I have never found or read any information concerning the best way to feed a base insulated tower. Is it better to just feed one leg from the matching network or would it be better to feed all three tower legs at the same time... OR... does it even make any difference at all? Any out there that have tried both ways? 2: Also..Now there is a static bleed choke across only one leg insulator of the vertical... Is it better with one on each leg across the base insulators? (each leg is insulated with T10 Garolite solid rod type insulators about 18 in long and milled to fit the Rohn 25 tower legs.. 4 in. insulated gap left between the upper tower and lower 2ft of tower left out of concrete base.) _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Msg from T6LG
I will keep trying low bands daily within the next 2 months. In the beginning of March I will remove all antennas and leave. It was good DX-pedition, but hope to do a bit more on low bands especially. Did not have so good setup and opportunity to install many antennas when I was in Iraq as YI9LZ. Listen for me on top band, I will do my best! Regards! Ilian, T6LG/LZ1CNN NOTE: Ilian also said he has constructed new lowband RX antennas to try.We can certainly appreciate his efforts. ___ Stew Perry Topband Distance Challenge coming on December 29th.
