Topband: Antenna network Vac Caps FS

Hello Top Banders - I have two Jennings vacuum variable caps available for your low band antenna project. Listings: https://www.eham.net/classifieds/600032 or search on my call: https://swap.qth.com/search.php

Re: Topband: Antenna check for V31XX

LU8DPM may have a very good station however it is summer in Argentina so QRN is likely much higher than Belize. It is ~4000 miles south of Belize. I have spent a lot of winters in Aruba and it was not unusual to see and hear the lightning storms in South America. John KK9A (P40A) Jim Brown K9YC

Re: Topband: Antenna check for V31XX

LU8DPM have had a receiving problem for years. Seems like he is unable to do something about it so the rest of us just have to run more power to work him. / Jim SM2EKM Den 2022-01-31 kl. 22:38, skrev Jim Brown: On 1/31/2022 12:13 PM, cqtestk4xs--- via Topband wrote: Any comments on the signal/

Re: Topband: Antenna check for V31XX

January 31 2022 6:15:45PM Subject: Topband: Antenna check for V31XX Well you were S4 on the meter on 21st Jan over here Bill . . . and most NA stations were only S5 that night, so conditions were poor. Were you using the same aerial then? Roger G3YRO _ Searchable Arch

Topband: Antenna check for V31XX

Well you were S4 on the meter on 21st Jan over here Bill . . . and most NA stations were only S5 that night, so conditions were poor. Were you using the same aerial then? Roger G3YRO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector

Re: Topband: Antenna check for V31XX

On 1/31/2022 12:13 PM, cqtestk4xs--- via Topband wrote: Any comments on the signal/condx would be appreciated. I had no problem hearing you, Bill, never heard V31MA. And LU8DPM is either seriously deaf or doesn't want to work US. 73, Jim K9YC _ Searchable Archives: http://www.

Re: Topband: Antenna check for V31XX

Hi Bill, I misunderstood, it looks like V31MA was running low power, so you would have to subtract off the difference in dB from your RBN data to see how it compares with V31MA. Don (wd8dsb) On Mon, Jan 31, 2022 at 4:30 PM Don Kirk wrote: > Hi Bill, > > You should still be able to compare your

Re: Topband: Antenna check for V31XX

Hi Bill, You should still be able to compare yourself to V31MA using the RBN data. Just find out how much power V31MA was running and compare it with your power level in units of dB. Then you can use the RBN data to compare your signal to V31MA as long as you subtract the dB difference in power f

Re: Topband: Antenna check for V31XX

Bill, I was not QRV this w/e.dealing with high winds, snow, and life. Any reports you get will be anecdotal, but...if you go to this link: http://beta.reversebeacon.net/analysis/ punch in the date you are interested in (I used Jan 31rst) and then punch in V31XX, then add V31MA you can see in gr

Re: Topband: Antenna check for V31XX

I worked you before and during the contest.  You were 5NN :-) Don't ask what you really were, but I have a really modest station, so you were doing something right.  TS-890, KPA500 and an inverted-L, 55 ft vertical, the rest horizontal (only 18 on ground radials).  I receive on the TX antenna a

Topband: Antenna check for V31XX

After  putting down 3600 yard staples to install 55 radials 130 ft for my 100 ft wire vertical with a 30 ft L I was ready for the 160 test.  For RX I used an SAL-30 which performed well at my old QTH in KH6. The only other V3 station was V31MA who has an excellent location close to the water wit

Topband: antenna matching unit for phasing 2 antennas

Just what the title says.I am trying to identify this unit.It is homebrew.I do not think built for commercial use as it has a push/pull switch for 80/160 meters.I cant send pictures via topband but can send to a personel e-mail.It is beautiful construction.Any help appreciated.Way to pretty to

Topband: Topband antenna description on my website updated

Hi, I updated the article about by 160/80 vertical. See: https://www.pa5kt.com/index.php/projects/15-vertical-for-160m-80m 73 Henk PA5KT _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector

Re: Topband: Antenna rope through pulleys...

I use military surplus pulleys. They have really narrow space between the pulley and the bracket. So never faced this problem. However, very nice and practical idea. Thanks for sharing. On Mon, 27 Sep, 2021, 01:26 , wrote: > > > > >If I think there might be an issue with the antenna rope jum

Re: Topband: Antenna thoughts

I would have to know just exactly how your "Ground R" was constructed to comment. The two EZNEC variables for ground description are dielectric constant and conductance. Also there is a lot depending on the T dimensions and L dimensions in any comparison that would preclude any simple answer that d

Re: Topband: Antenna thoughts

On 3/2/2021 11:19 AM, Dave Cuthbert wrote: John, here are EZNEC results for your downward sloping inverted-L and your T-vertical. Inverted-L radiation resistance = 8 ohms T-vertical radiation resistance = 12 ohms When doing these comparisons on 160 meters, it is crucial to use the EZNEC "D

Re: Topband: Antenna thoughts

John, here are EZNEC results for your downward sloping inverted-L and your T-vertical. Inverted-L radiation resistance = 8 ohms T-vertical radiation resistance = 12 ohms How the radiation efficiency compares depends on your ground system. The efficiencies for 2.5, 5, and 10 ohm ground systems are

Re: Topband: Antenna thoughts

ase loading to get a good match. TomW3TA -Original Message- From: GEORGE WALLNER To: John ; topband@contesting.com Sent: Tue, Mar 2, 2021 9:28 am Subject: Re: Topband: Antenna thoughts John, For DX, the T will be better than the L, especially if part of the L is sloping. (Higher radiation resistance.

Re: Topband: Antenna thoughts

Hi John, I think a tee is an excellent antenna for DX and as others have mentioned and that’s what I would us but thought I should mention something regarding NVIS capabilities. I suspect a tee is deaf as can be for NVIS signals just like my 68 foot base loaded vertical that I use on 160 meters.

Re: Topband: Antenna thoughts

ox 52' with the tee wires extending out from there. Had to add a bit of base loading to get a good match. TomW3TA -Original Message- From: GEORGE WALLNER To: John ; topband@contesting.com Sent: Tue, Mar 2, 2021 9:28 am Subject: Re: Topband: Antenna thoughts John, For DX, the T will be be

Re: Topband: Antenna thoughts

John, For DX, the T will be better than the L, especially if part of the L is sloping. (Higher radiation resistance.) Also, if the two loading wires are the same length, the antenna will be good on 3.5 and 7 MHz. Regarding the radials, it all depends on how many and how long you have now, but t

Topband: Antenna thoughts

Hello all.I currently have a coaxial inv. L.apex at 50ft and rest going out at abt 45 degrees.The end is abt 20-30 ft high.It has been a very good antenna.I used a l because I did not have the option of 2 masts.I am changing a bit.Doing away from vhf/uhf beams.So I have another 50 ft mast.They a

Topband: Antenna switching relay

RF Parts has corrected their BLOG for the VHC-3 vacuum relay to 12 VDC coil voltage. They have a limited supply of them in stock. 73 Bruce-k1fz _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector

Re: Topband: Antenna work Hazard

In addition to tall weeds and bushes, that will also handle trees up to 6" diameter. Afterward, all that's left on the earth is a flat, clear path of soil and mulch. And I have many hard chert rocks. It even took care of those! :-) I just carried them over to a rock pile. 73, Mike www.w0btu.com

Re: Topband: Antenna work Hazard

Bruce, I had some very dense growth removed by hiring someone with a skid steer equipped with a grinding and mulching attachment. In comparison, it makes a brush/bush hog look like a walk-behind mower! That thick growth was gone in no time, and so I was finally able to easily get at one one of my

Topband: Antenna work Hazard

For those who do not know. The tic subject was about dealing with the danger while doing antenna. work. A drone aerial spraying poison possibility was too expensive. Other protective methodswere posted. Thanks to everyone for your help and Ideas. 73,Bruce-k1fz ---

Re: Topband: Antenna Switch isolation capacitor

The Ameritron RCS-4 uses three .01uF 1kV disc capacitors in parallel in this position. I don't think 4 ohms of XC is a biggie in the antenna system SWR, but increased current handling capability of paralleled capacitors is a real advantage at legal limit. Tim N3QE On Tue, Jun 25, 2019 at 4:30 PM

Re: Topband: Antenna Switch isolation capacitor

The capacitor value is OK, but disc ceramics do handle current well. 73Bruce, k1fz -From: k...@voyager.net To: topband@contesting.com Cc: Sent: Tuesday June 25 2019 4:22:27PM Subject: Topband: Antenna Switch isolation capacitor Hi All, A friend

Topband: Antenna Switch isolation capacitor

Hi All, A friend on 160 has had a problem with a Heathkit remote antenna switch due to a partial failure of the isolation capacitor in the remote unit. It is a .02 uF 1.6 KV disc ceramic that isolates the DC from the antennas. Since this results in about 4.4 ohms of XC - capacitive reactance in

Topband: Antenna Forum at Hamvention - this Friday afternoon

2:00 PM - 5:00 PM Antenna Forum at Hamvention in Xenia, Ohio, Room 1 Moderator: Tim Duffy, K3LR. "How to Use Your Tower as a Dual-Band Single-Feed 80 meter/160 meter Vertical Antenna Using No Traps, Switches, or Tuners - And Extensions to Phased Arrays" - Dr. Ted Rappaport, N9NB and Jim Parnell

Re: Topband: antenna analyzers

I can now verify that the FA-VA5 does just fine on my 160 meter inverted-L. As an aside, we've had some rain here in Tucson lately and I've observed a decrease in the feedpoint Z of about 5 ohm due to increased ground conductivity.  Welcome, but I know it's temporary. Wes  N7WS On 10/12/20

Re: Topband: antenna analyzers

At this location, the VNWA is a bit squirly near the BC band but with a single L/C notch added at the device input (within the cal plane), it works fine. The AA-55 Zoom I have is immune and is the my go-to instrument for field work.  Recommended. MFJ-259 is too easily disturbed and is not re

Re: Topband: antenna analyzers

I can vouch for the AA-55 Zoom, although it is not without flaws. I live 5.9 miles from a 50KW BC station on 1550 kHz.  On my 160-meter inverted-L they are 70 dB over S9 on a calibrated K3, that's 70 dB above -73 dBm or -3dBm. As long as I don't sweep through that frequency, the analyzer is unfa

Re: Topband: antenna analyzers

On 10/12/2018 12:02 PM, AC0RL via Topband wrote: I have found that antenna analyzers can get screwed up on long antennas if there are nearby transmitters; AM stations or any other transmitter that can swamp out the input to the analyzer. I live 1/4 mile from a 1kw am station and I cannot use

Topband: antenna analyzers

In response to: Recently Tree did some work for me and one of the things was to put up the Comtek 80 meter 4-Square switching unit and a couple of pulley setups for my raising of the 80meter slopers. Lately I've been chasing my tail around to get them dipped in around 3700-3750 Khz.

Topband: Antenna at a sea cliff

Hello, To take leverage of the location and direction at which the cliff faces, what kind of antenna would you set up in a place where the TRX would be on the top of a cliff, 50 to 80m above sea level? 73, Felipe CT7ANO, PY1NB _ Topband Reflector Archives - http://www.contesting.

Re: Topband: Antenna Switches

The two RAS-8x2 units have been claimed. I'll post a note if anything changes. 73, Gary K9AY _ Topband Reflector Archives - http://www.contesting.com/_topband

Topband: Antenna Switches

I have two RAS-8x2 RX antenna switch units available for immediate shipment (75 ohm, F connectors). I made a couple extras while putting together some custom systems. E-mail me or check the website - aytechnologies.com Waiting for summer t'storms to be over! 73, Gary Breed K9AY ___

Topband: ANtenna

Mike: Given the stated constraints, I'd put traps on the ends of the 80 meter inverted vee and add more wire to make a 160 meter inverted vee. If you are short on space, fold the ends in towards the center. regards, Larry W8ANT _ Topband Reflector Archives - http://www.contestin

Re: Topband: Antenna Impedance Measurements

I couldn't find a price for the AA-170. Can you share it, as well as the place of purchase? Thanks, Mike www.w0btu.com On Mon, Mar 28, 2016 at 4:55 PM, Dick Bingham wrote: > Many thanks to those who sent recommendations for portable antenna > impedance measurement tools. I will purchase the AA-

Topband: Antenna Impedance Measurements

Many thanks to those who sent recommendations for portable antenna impedance measurement tools. I will purchase the AA-170 and smile all the way to the bank. . . 73 Dick/w7wkr CN97uj _ Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Antenna Tuners

I cut my top loaded "T" (85' at top, 10' high feed, elevated 8x 125' radials) for 1825. Then 3 equal value series capacitors are shorted by PCB relays (10a, 5Kv coil insulation) to switch in C, C/2, and C/3 (C=4000pf for this antenna). That yields 4 by 40KHz spaced segments with > 50KHz 2:1 b

Re: Topband: Antenna Tuners

Jim, I mentioned relay cut-in of L's and/or C's at the base of an antenna to help cover all of 160M. On my tuner web page I mentioned does not show this recent update I have made at my shack, but I have a relay that shunts out turns of my 160M coil to help me QSY to top end of 160M phone in contest

Re: Topband: Antenna Tuners

My opinions: All-band antenna tuners make a set of compromises to produce a tuner that fits in one box. They may not be able to handle legal limit on RTTY. Or legal limits CW/SSB on other bands, especially the "extreme bands" of 10M and 160M. They often have 10-turn (or more-turn) roller inducto

Re: Topband: Antenna Tuners

> I have e-mailed Palstar but, to date, they have not responded. I would > love it if someone would come up with a high power, fully weatherized, > remote tuner. I was in a dilemma back in Illinois, I had a Heights 100' aluminium fold over tower but insufficient land to put down sufficient radi

Re: Topband: Antenna Tuners

As a point of reference, in the product manual for the Palstar auto tuner, they do mention developing a remote version of their auto tuner. PALSTAR will offer a fully remote version of the base version in the near future. However, in certain cases where there is DC power available at a reasonab

Re: Topband: Antenna Tuners

I have been successfully using the MFJ-998RT successfully on a 2 el 80M phased wire array. The 2 el wire beam has great performance but is very narrow banded (about 100khz) so I decided to try this tuner mounted on the tower at the feed point of the connection to the 2 phasing cables. It works su

Re: Topband: Antenna Tuners

I have started looking at tuners myself and was mainly interested in auto tuners. There are some that claim to handle the legal limit except for RTTY. I have a Dentron MT3000A manual tuner and it doesn't seem to care. OTOH most of my antennas usually don't need a tuner as I have had solid stat

Re: Topband: Antenna Tuners

On Sun,2/14/2016 6:30 PM, Jim Murray via Topband wrote: would appreciate any opinions My favorite has long been the Ten Tec 229/238 series of tuners. All essentially the same, except that the latest models use mechanical vernier indication of inductor position rather than a dial string (a ma

Re: Topband: Antenna Tuners

Jim, You are undoubtedly going to get a variety of recommendations on a tuner. I guess the first thing to decide is if you really want an automatic tuner. Secondly it if you are going to use balanced line or not. And last but not least power level you will be using. I have a Palstar AT5K wh

Topband: Antenna Tuners

Hello all,Would you have any recommendations for antenna tuners?  Have been looking at the automatics, Palstar, Mfj, LDG At-1000Proii etc..  Have been using an old Dentron which doesn't have very close markings on the dials and getting tired of turning and adjusting.  Another option would be ano

Topband: antenna modification

have hy-18ht with 80/160 tapped coil. would like to try the inverted L configuration. i do not have a 40m trap as provided in the L kit, but i have no need for 40m at this time. so if i just don't use 40m, could i remove the 160 section from the coil and simply add the L extension to resonan

Topband: antenna question

This question is about bi-directional beverages, or more specifically BOG's using a reflection transformer. How does the loss on the forward and reverse direction compare to an omnidirectional reference antenna? I am not sure I worded that properly, but let's say the following was observed. Refe

Re: Topband: Antenna relays

I agree generally with these comments, except that my experience with CdAg contacts on receiving hasn't been that bad, provided that the application exercises the relays occasionally. Thus, using them as, e.g., an outdoor antenna switch where the antenna isn't regularly switched, and where there a

Re: Topband: Antenna relays

I agree generally with these comments, except that my experience with CdAg contacts on receiving hasn't been that bad, provided that the application exercises the relays occasionally. Thus, using them as, e.g., an outdoor antenna switch where the antenna isn't regularly switched, and where there ar

Re: Topband: Antenna relays

With silver-cadmium relay contacts I use on my ladder line switching, I find I have to occasionally transmit a dit to get receive to work again, especially if I haven't been on the radio in hours or days. My mental model is that I have to "blow through" the surface contamination. Would definitel

Re: Topband: Antenna relays

With silver-cadmium relay contacts I use on my ladder line switching, I find I have to occasionally transmit a dit to get receive to work again, especially if I haven't been on the radio in hours or days. My mental model is that I have to "blow through" the surface contamination. Would definitely n

Re: Topband: Antenna relays

DC or low frequency AC is an almost meaningless test, although field life is a good data point. The only valid bench tests for a relay in these applications are RF heating with high current, and voltage breakdown. Some relays even run current or voltage through the coil pole center, making a

Re: Topband: Antenna relays

For my StationPro controller I tested a variety of relays and eventually settled on the Tyco/Shrack (Mouser 655-RTB14012F). There are about 3000 of these relays in use now by StationPro builders, with no failures reported except for one defective relay with an open coil. All the SP builders run QRO

Re: Topband: Antenna relays

Are you hot-switching these? Or, could they be placed at a point where the current is higher than the relay's rating? In any case, I bought three or four different replays based on a discussion here (around October 9, 2014), and FWIW, I see just now that none of them are Omron G6RN. They are: Mou

Re: Topband: Antenna relays

hoppa Sent: Sunday, May 17, 2015 10:55 PM To: topBand List Subject: Topband: Antenna relays I think I posted some details here about how I was using Omron G6RN antenna relays (same as used in AC0HB's QEX article) for antenna switching of my coax cables. These are very affordable (circa $3) 8A

Topband: Antenna relays

I think I posted some details here about how I was using Omron G6RN antenna relays (same as used in AC0HB's QEX article) for antenna switching of my coax cables. These are very affordable (circa $3) 8A SPDT relays and they held up OK for me in heavy contest usage - until I got a legal limit amp. S

Re: Topband: Antenna isolation measurements (3)

erage position trade-offs on the farmers'field. Tnx es 73, Michel, ON7EH -Original Message- From: on7eh Sent: Wednesday, February 04, 2015 10:37 PM To: topband@contesting.com Cc: on...@skynet.be Subject: Re: Topband: Antenna isolation measurements Setup 3 below was retained

Re: Topband: Antenna isolation measurements

: Michel Spelier Sent: Tuesday, January 27, 2015 10:29 PM To: topband@contesting.com Cc: on...@skynet.be Subject: Antenna isolation measurements Prior to the CQWW160, we did some (topband) antenna isolation measurements between: -a quarterwave inv L (top at 15m down to 11m) and -a new

Topband: Antenna isolation measurements

Prior to the CQWW160, we did some (topband) antenna isolation measurements between: -a quarterwave inv L (top at 15m down to 11m) and -a new unterminated beverage (0.8m high) of different lengths (via a 9:1 transformer) and 2 different locations. The Bev used PVC-covered 0.6mm thick twisted pair

Re: Topband: Antenna patterns (in close)

AutoEZ can display near field data on polar, rectangular, and 3D plots. For several illustrated examples see section "Electric or Magnetic Field Strength - Near Field" here: http://ac6la.com/aepatterns.html AutoEZ home page: http://ac6la.com/autoez.html Dan, AC6LA _ Topban

Topband: Antenna patterns (in close)

Is there a cheap program that calculates and *displays* antenna patterns in close to the antenna? I'm working on a better way to explain the limits of using receiving directivity, and explain why what might be phenomenal "this is the best thing ever" to one person might be "don't work for crap

Topband: Antenna work and protection

Ladies and Gents,   Please as you do your yearly antenna building/repair chores give some thought to protecting yourselves from Mosquitos and ticks.  Lyme disease is particularly bad here in Maryland and throughout the northeastern part of the country.  Check with your health professional fo

Re: Topband: Antenna question

I agree with everything Tom has stated here, with one MAJOR exception. The generic audio "rack cable" that is twisted pair with a foil shield and drain wire as made by Belden and everyone alse is a TRAIN WRECK for RF intrusion from the shield to the pairs. The drain wire is the bad guy -- no p

Re: Topband: Antenna question

On 3/28/2014 6:23 AM, Tom W8JI wrote: There is no reason why it won't work or why shielded wire won't work with proper transformers and wiring. I agree with everything Tom has stated here, with one MAJOR exception. The generic audio "rack cable" that is twisted pair with a foil shield and dr

Re: Topband: Antenna question

rom a 600' 2 wire running 90 degrees away and fed at its far end. I cant tell any affect on its performance or the new one with either connected or one floating, or both. Carl KM1H - Original Message - From: "Bruce" To: Sent: Thursday, March 27, 2014 7:43 PM Subje

Re: Topband: Antenna question

ot;kd9sv" To: "'Bruce'" ; "'Herbert Schonbohm'" Sent: Friday, March 28, 2014 9:55 AM Subject: FW: Topband: Antenna question Herb and Bruce, apparently the reflector stripped the attachment of so I am resending this to both of you...de

Re: Topband: Antenna question

I would like to see if anyone actually tried the wire, and if it rejected any portion of RF signals. How would someone measure "rejected any portion of RF signals" in a meaningful, quantitative, way? _ Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Antenna question

Has anyone on the reflector ACTUALLY tried two wire audio twisted pair for a 2 wire, two direction Beverage antenna. If yes, how did it work ? Notice any added directional properties? There is no reason why it won't work or why shielded wire won't work with proper transformers and wiring.

Re: Topband: Antenna question

Floating the shield may even make it work better? This shield could be used as the antenna, and the inner pair as the transmission line. That would work fine. _ Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Antenna question

Floating the shield may even make it work better? Herb Schoenbohm, KV4FZ On 3/28/2014 9:23 AM, Tom W8JI wrote: Has anyone on the reflector ACTUALLY tried two wire audio twisted pair for a 2 wire, two direction Beverage antenna. If yes, how did it work ? Notice any added directional propertie

Re: Topband: Antenna question

these transformer sets are available from DXE 73, de gary -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Herbert Schonbohm Sent: Friday, March 28, 2014 7:29 AM To: topband@contesting.com Subject: Re: Topband: Antenna question If Cat 5 cable will work

Re: Topband: Antenna question

If Cat 5 cable will work why won't two wire twisted air audio cable? Is it because of the tightness of the twist that is of concern. I see no reason it won't work except for the cancellation property of twisted pair but with a Beverage we are dealing with a different wire signal propagation med

Topband: Antenna question

Intriguing question ? Has anyone on the reflector ACTUALLY tried two wire audio twisted pair for a 2 wire, two direction Beverage antenna. If yes, how did it work ? Notice any added directional properties? 73 Bruce www.qsl.net/k1fz/beveragenotes.html _ Topband Reflector Arch

Re: Topband: Antenna matching question

Hi Ray, All of this is traceable to real causes, and can be repeated in tests and measurements. This is something I learned through experience in 1970 building homebrew amps, and it repeats in everything from antenna tuners to amplifiers. I have burn up two output band switches on my Ameri

Re: Topband: Antenna matching question

I have burn up two output band switches on my Ameritron AL1200 while on 160m. The amp uses a single 3CX1200A7 tube. My swr may have been high, but less that 3:1. Could the discussion above be the same for the AL1200 amp? I'm tired of replacing the band switch. I looked at replacing it with a large

Re: Topband: Antenna matching question

Wrong reflector, but I disagree completely with this: The HV build up was mitigated by the 10pf cap between the 40-20M positions which also reduces arcing on the SB-220 which is a shorting switch and a cap can be adapted to some 160-10M amps. The right hand one in that photo had the 80-40M co

Re: Topband: Antenna matching question

KM1H - Original Message - From: "Tom W8JI" To: "Carl" ; "Bill Wichers" ; Sent: Tuesday, March 18, 2014 9:55 PM Subject: Re: Topband: Antenna matching question If this is only 160-40 you probably won't have a series resonance issue with unused

Re: Topband: Antenna matching question

I have an amplifier with a pair of 3-400Zs I built in the 60s. When I built it it was for 20, 15 and 10 meters. I used 3 of the 5 positions of a BC375 tuning unit switch. Everything work fine. I added 160, 80 and 40 meters. 160 was switched in and out with a RJ-1a vacuum relay. When I went to 20

Re: Topband: Antenna matching question

Tom,  I have an amplifier with a pair of 3-400Zs I built in the 60s. When I built it it was for 20, 15 and 10 meters.  I used 3 of the 5 positions of a BC375 tuning unit switch. Everything work fine. I added 160, 80 and 40 meters.  160 was switched in and out with a RJ-1a vacuum relay. When I we

Re: Topband: Antenna matching question

If this is only 160-40 you probably won't have a series resonance issue with unused turns, but if you cover a wide range you will want to progressively short the large coil taps. This is why band switches that do not short (like the old National amp) and why large roller inductors mess up on hi

Re: Topband: Antenna matching question

- Original Message - From: "Tom W8JI" To: "Bill Wichers" ; Sent: Tuesday, March 18, 2014 5:33 PM Subject: Re: Topband: Antenna matching question You mention keeping the highest impedance part "clean" electrically, which would make me think putt

Re: Topband: Antenna matching question

You mention keeping the highest impedance part "clean" electrically, which would make me think putting the small coil nearest the anteanna would be best. Whichever part of the inductor is shunted out is essentially just adding stray capacitance, that keeps the shorted turns part of the inductors

Re: Topband: Antenna matching question

The inductors are homebrew, but beefy. Basically I use 1/8" thick G10 phenolic with holes drilled in a cross vise (to maintain spacing), 8 gauge wire for the windings, and three aluminum brackets shaped like this \___/ arranged like a triangle on each end to hold the G10 in place. It ends up mak

Re: Topband: Antenna matching question

Here's my question: the large inductor is much higher Q on 160 than the small inductor (large inductor is about 4.5" diameter, small one about 2" diameter). Would it be better to have the large inductor connected to the antenna and the small one to the feed (the two inductors would still be in

Topband: Antenna matching question

I'm working on a new matching network for my vertical. The vertical is a wire cage of approx. 82 feet high, and I use it on 160, 80 and 40 meters. The matching network is a low-pass L network. The new matching network is remotely tunable with 5 different capacitors selected by vacuum relays and

Re: Topband: Antenna Help

I have an antenna that I originally built for 75m. It is 72 feet tall which is .280 wavelength instead of 1/4 wavelength. This gives a resistive feed point of 52 ohms and an inductive reactance tuned out by a series capacitor. On 160m I use 34 feet of linear loading and a coil to make up the r

Re: Topband: Antenna Help

On 1/31/2014 4:36 PM, Chortek, Robert L wrote: Thinking about a simple 30-160 meter vertical system with minimal compromises: What I had that worked was a 90 foot vertical with insulators at 30 and 60 feet. Relays shorted out the insulators, so that I could have a 30 foot vertical for 40, a

Topband: Antenna Help

Thinking about a simple 30-160 meter vertical system with minimal compromises: 60 foot tapered aluminum 1/4 wave in 80, plus, Run two 1/4 wave wires from the base to standoffs mounted at the appropriate heights, plus , Another wire from the base to the top with a standoff mounted there and thre

Re: Topband: Antenna Question

Do you think a Nye would tune my antenna to 160/80/40 if I extended it to 43 feet or so? Base voltage problems?>> With 500 watts actually applied to a 43 foot vertical made of 1 inch tubing, the base voltage is about 14 kV peak. With standard 1/4 inch bolts forming the arc electrodes, 14 kV w

Re: Topband: Antenna Question

MMANA, please let me know. So I am off 160m for the time being.     Regards, Raoul ZS1REC             From: Jim Brown To: topband@contesting.com Sent: Monday, December 9, 2013 8:59 PM Subject: Re: Topband: Antenna Question On 12/9/2013 10:47 AM, Ashton Lee wrote: > The 43 foot antennas

Re: Topband: Antenna Question

On 12/9/2013 10:47 AM, Ashton Lee wrote: The 43 foot antennas are very short (low inductance, poor efficiency) on 160. Only my very best tuners will tune them… and tuning doesn’t make them efficient, it only makes them not destroy the radio with reflected currents. The best solution is to top

Re: Topband: Antenna Question

The 43 foot antennas are very short (low inductance, poor efficiency) on 160. Only my very best tuners will tune them… and tuning doesn’t make them efficient, it only makes them not destroy the radio with reflected currents. The best solution is to top load a 43 food antenna and turn it into an

Topband: Antenna Question

Hi all, My current LB antenna is an old Create 40/80 Vertical mounted about 20 feet off the ground with a bunch of radials at the base. I removed the Create 40 M trap and extended the mast to about 35 feet. At about 33 feet I have a homemade 40M trap in a horizontal wire out about 85 feet with

Re: Topband: Antenna switch rating for high SWR?

PM To: Joe Subich, W4TV; topband@contesting.com Subject: Re: Topband: Antenna switch rating for high SWR? The rub with any of this is the contact-to-coil breakdown. - Original Message - From: "Joe Subich, W4TV" To: Sent: Sunday, October 20, 2013 12:57 PM Subject: Re: Topban

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