Re: Topband: Using 80m 1/4 vertical on 160
Mike, No need for traps and horizontal wires and such. Put a 160 resonator on top of that vertical. Use a low Q long skinny coil with a nice big capacity hat of 25 pico farads or so. It won't affect 80 meters and will only be down 2 db or less than a full 160 quarterwave, with a good ground system like you have. I can give you the specifics for the resonator if you wish. Refer to the QEX articles on "Short Loaded Antennas" in the Jan/Feb and Mar/ Apr issues for the figures. 73, Barry, W9UCW _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Using 80m 1/4 vertical on 160
My current antenna is somewhat what you ask about Mike, its 70 ft vertical with two top hat wires to resonate at 1830. the top hat wires slope down to perhaps 20 ft high. For 80 meters I switch in a matching network of a coil to ground and a vacuum cap in series with the feed line. SWR tunes easy to 1 to 1 on 80. Modeling the antenna shows a small improvement over an 80 meter quarter wave, and has proved to be so in operation. Caution, there is very high voltage on the feedpoint on 80 meters and it takes a good vacuum relay to switch the antenna from 160 to the 80 network, I found a large vacuum relay for very high voltage on ebay for 5 bucks, no one else wanted it I guess. 73 Merv K9FD/KH6 Hello Mike, There are a couple of guys in IL that have 80M zero-five verticals with a vacuum relay at the top. The relay switches in a top loading wire to make an inverted L/T antenna for 160M. They run the control wires down the inside of the tubing. On 6/2/2014 10:09 PM, W0MU Mike Fatchett wrote: Thanks all for the comments. I am putting up a single DXE 80m 1/4 vertical. I can put out the proper radials. I will have to add some longer ones for 160. Now to figure out switching in and out 160 and the matching. Mike W0MU On 6/1/2014 10:49 PM, W0MU Mike Fatchett wrote: Is this worth trying? _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Using 80m 1/4 vertical on 160
I though about using relays to switch in/out the top loading wires for 160m, but computed the voltage to be over 10 KV. Vacuum relays to handle that voltage are very expensive. Then there is the issue of protecting them from harsh WX. Ray, N6VR I tried vacuum relays and they seemed to fail after around 6 months. After replacing them 4 or 5 times, I changed to using a big contactor, modified as described in QST May 2009, page 66 to increase the voltage handling. My modified relay has now been going strong for 5 years without a problem. It is mounted in a plastic box to protect it from the weather. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 50 ohm direct burial coax cable
You might want to check out Davis Bury-flex. I have used in in conduit - under water, for several years with no problems. Bruce W8RA From: "mstang...@comcast.net" To: Bill Wichers Cc: topband@contesting.com Sent: Tuesday, June 3, 2014 11:18 AM Subject: Re: Topband: 50 ohm direct burial coax cable Bill, Thanks. I will check it out. Mike N2MS - Original Message - From: Bill Wichers To: mstang...@comcast.net, topband@contesting.com Sent: Tue, 03 Jun 2014 14:58:51 - (UTC) Subject: RE: 50 ohm direct burial coax cable Usually "direct burial" cable is just a PE jacket with a flooding compound in the braid. Times Microwave makes a direct burial variant of their LMR-400 called "LMR-400-DB". It adds a flooding compound in the braid. The flooding compound will seal small fractures in the jacket. BTW, for everyone, there is a new "dry" type of water blocking compound used in fiber optic cables that is usually in the form of a powder or a yarn. When it gets wet it expands and seals the damaged cable area. It's lots easier to work with than the more traditional gel-type flooding compounds. Maybe if we're lucky we'll see someone start making coax that way! -Bill _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 50 ohm direct burial coax cable
Bill, Thanks. I will check it out. Mike N2MS - Original Message - From: Bill Wichers To: mstang...@comcast.net, topband@contesting.com Sent: Tue, 03 Jun 2014 14:58:51 - (UTC) Subject: RE: 50 ohm direct burial coax cable Usually "direct burial" cable is just a PE jacket with a flooding compound in the braid. Times Microwave makes a direct burial variant of their LMR-400 called "LMR-400-DB". It adds a flooding compound in the braid. The flooding compound will seal small fractures in the jacket. BTW, for everyone, there is a new "dry" type of water blocking compound used in fiber optic cables that is usually in the form of a powder or a yarn. When it gets wet it expands and seals the damaged cable area. It's lots easier to work with than the more traditional gel-type flooding compounds. Maybe if we're lucky we'll see someone start making coax that way! -Bill _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 50 ohm direct burial coax cable
Bill, Thanks. I will check it out. Mike N2MS - Original Message - From: Bill Wichers To: mstang...@comcast.net, topband@contesting.com Sent: Tue, 03 Jun 2014 14:58:51 - (UTC) Subject: RE: 50 ohm direct burial coax cable Usually "direct burial" cable is just a PE jacket with a flooding compound in the braid. Times Microwave makes a direct burial variant of their LMR-400 called "LMR-400-DB". It adds a flooding compound in the braid. The flooding compound will seal small fractures in the jacket. BTW, for everyone, there is a new "dry" type of water blocking compound used in fiber optic cables that is usually in the form of a powder or a yarn. When it gets wet it expands and seals the damaged cable area. It's lots easier to work with than the more traditional gel-type flooding compounds. Maybe if we're lucky we'll see someone start making coax that way! -Bill _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: duo-band 80m/160m antenna
All, I had a quarter-wave 80m wire vertical (thanks to a pulley under the limb of an 80ft tall oak tree) with three elevated radials. Worked great. I bought a length of 3-inch OD B&W inductor stock and got some high-voltage door-knob capacitors to make an 80m trap. Put it at the top of the 80m vertical, added three 120ft elevated radials and added a wire that slanted back to the house to resonate it on 160m. it took some extra work, but it was a nice duo-band antenna with my single 3CX800 amp. Carl K9LA What about two seperate antennas with a common feed? Have the 80 as a vertical and the 160 spaced from it a foot or so and then go to a L or T at the top? If 80 is an aluminum tube then U bolt on a plate with an insulator extending out for the standoff. Carl KM1H _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 50 ohm direct burial coax cable
Usually "direct burial" cable is just a PE jacket with a flooding compound in the braid. Times Microwave makes a direct burial variant of their LMR-400 called "LMR-400-DB". It adds a flooding compound in the braid. The flooding compound will seal small fractures in the jacket. BTW, for everyone, there is a new "dry" type of water blocking compound used in fiber optic cables that is usually in the form of a powder or a yarn. When it gets wet it expands and seals the damaged cable area. It's lots easier to work with than the more traditional gel-type flooding compounds. Maybe if we're lucky we'll see someone start making coax that way! -Bill > -Original Message- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of > mstang...@comcast.net > Sent: Tuesday, June 03, 2014 10:10 AM > To: topband@contesting.com > Subject: Topband: 50 ohm direct burial coax cable > > Does anyone know of a source for 50 ohm "RG-8" type direct burial coax > able. > > I can find many sources for CATV and Satellite 75 ohn cable but not 50 ohm. > > Direct burial cable is coated with and anti-fungal compound. I''ve had success > with 75 ohm cables for receiving and want to purchase 50 ohm direct burial > for transmitter feeds. > > Thanks, > > Mike N2MS > _ > Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: doorknob caps
Bill, I used four 75pF 5kV caps (I think I bought them from the local surplus shop when it existed). I put two in parallel, and in series with that were the other two in parallel. Thus it was a 75pF/10kV assembly. The coil was cut to resonate at 3550 KHz or so. Carl K9LA _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 50 ohm direct burial coax cable
http://www.davisrf.com/buryflex.php 73, Jim N7US -Original Message- Does anyone know of a source for 50 ohm "RG-8" type direct burial coax cable? I can find many sources for CATV and Satellite 75 ohn cable but not 50 ohm. Direct burial cable is coated with and anti-fungal compound. I''ve had success with 75 ohm cables for receiving and want to purchase 50 ohm direct burial for transmitter feeds. Thanks, Mike N2MS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: 50 ohm direct burial coax cable
Buryflex is a good one. 73, Jorge CX6VM/CW5W Enviado desde mi iPhone > El 03/06/2014, a las 11:10, mstang...@comcast.net escribió: > > Does anyone know of a source for 50 ohm "RG-8" type direct burial coax able. > > I can find many sources for CATV and Satellite 75 ohn cable but not 50 ohm. > > Direct burial cable is coated with and anti-fungal compound. I''ve had > success with 75 ohm cables for receiving and want to purchase 50 ohm direct > burial for transmitter feeds. > > Thanks, > > Mike N2MS > _ > Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: duo-band 80m/160m antenna
All, I had a quarter-wave 80m wire vertical (thanks to a pulley under the limb of an 80ft tall oak tree) with three elevated radials. Worked great. I bought a length of 3-inch OD B&W inductor stock and got some high-voltage door-knob capacitors to make an 80m trap. Put it at the top of the 80m vertical, added three 120ft elevated radials and added a wire that slanted back to the house to resonate it on 160m. it took some extra work, but it was a nice duo-band antenna with my single 3CX800 amp. Carl K9LA _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: 50 ohm direct burial coax cable
Does anyone know of a source for 50 ohm "RG-8" type direct burial coax able. I can find many sources for CATV and Satellite 75 ohn cable but not 50 ohm. Direct burial cable is coated with and anti-fungal compound. I''ve had success with 75 ohm cables for receiving and want to purchase 50 ohm direct burial for transmitter feeds. Thanks, Mike N2MS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Using 80m 1/4 vertical on 160
I have the zero five 55 foot antenna which was custom built to actually be a full sized 80 meter antenna. It was affordable and has stood up well on a very windy mountain top. Performance is, of course, no different than a 65 foot wire…. if you had trees to support the latter. On Jun 3, 2014, at 1:43 AM, Ray Benny wrote: > Mike, > > Can you find or provide more info on these 80m zero-five verticals? What > does zero-five mean or stand for? > > I though about using relays to switch in/out the top loading wires for > 160m, but computed the voltage to be over 10 KV. Vacuum relays to handle > that voltage are very expensive. Then there is the issue of protecting them > from harsh WX. > > Ray, > N6VR > > > On Mon, Jun 2, 2014 at 9:39 PM, Jim Brown wrote: > >> On 6/2/2014 6:07 PM, John Kaufmann wrote: >> >>> Perhaps top loading would be somewhat more efficient on 160, >>> but it would be difficult electrically and mechanically to switch out top >>> loading on 80. >>> >> >> Not as difficult as you might think. Certainly worth some modeling. Add a >> 80M trap at the top between the vertical and horizontal portions. Below 80M >> that circuit would look inductive, which adds loading on 160. In the model, >> play with values for the trap and the top wires to maximize efficiency. My >> guess it that might be good for another dB or two. >> >> >> 73, Jim K9YC >> _ >> Topband Reflector Archives - http://www.contesting.com/_topband >> > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Using 80m 1/4 vertical on 160
I used Deltrol relays from Surplus Sales of Nebraska to switch my matching, $24 and rated at 6kV from memory. Working fine at 400W even on my very short radiator. -Original Message- From: Tom W8JI Sent: Tuesday, June 03, 2014 2:14 PM To: W0MU Mike Fatchett ; topband@contesting.com Subject: Re: Topband: Using 80m 1/4 vertical on 160 I am putting up a single DXE 80m 1/4 vertical. I can put out the proper radials. I will have to add some longer ones for 160. That's a good vertical, and the 80M radials will probaby be adequate if you have enough of them. Now to figure out switching in and out 160 and the matching. That is always the difficult part. If you have a good ground system and high efficiency, voltage can get pretty high when on the higher band for a top wire, and the lower band for switching a coil. Many systems work at high power because of losses. If you just want to run outside to change bands, it is easy. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Using 80m 1/4 vertical on 160
I am putting up a single DXE 80m 1/4 vertical. I can put out the proper radials. I will have to add some longer ones for 160. That's a good vertical, and the 80M radials will probaby be adequate if you have enough of them. Now to figure out switching in and out 160 and the matching. That is always the difficult part. If you have a good ground system and high efficiency, voltage can get pretty high when on the higher band for a top wire, and the lower band for switching a coil. Many systems work at high power because of losses. If you just want to run outside to change bands, it is easy. _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Using 80m 1/4 vertical on 160
Mike, Can you find or provide more info on these 80m zero-five verticals? What does zero-five mean or stand for? I though about using relays to switch in/out the top loading wires for 160m, but computed the voltage to be over 10 KV. Vacuum relays to handle that voltage are very expensive. Then there is the issue of protecting them from harsh WX. Ray, N6VR On Mon, Jun 2, 2014 at 9:39 PM, Jim Brown wrote: > On 6/2/2014 6:07 PM, John Kaufmann wrote: > >> Perhaps top loading would be somewhat more efficient on 160, >> but it would be difficult electrically and mechanically to switch out top >> loading on 80. >> > > Not as difficult as you might think. Certainly worth some modeling. Add a > 80M trap at the top between the vertical and horizontal portions. Below 80M > that circuit would look inductive, which adds loading on 160. In the model, > play with values for the trap and the top wires to maximize efficiency. My > guess it that might be good for another dB or two. > > > 73, Jim K9YC > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
