Re: Topband: choke/bleeder resistor on RXvertical?
Precisely, Peter! There was no DC path to ground on my inverted-L, because the tuner at the base was just two or three capacitors. A spark gap across the resistor will also discharge surge voltages from nearby lightning strikes. The tips of my homebrew shunt spark gap melted more than once from that. And that's why I use Ohmite Type OY resistors for that. 73, Mike www.w0btu.com On Sat, Dec 22, 2018, 10:55 AM Peter Bertini wrote: > A drain resistor would be advisable if there is no DC return path to > earth... if there is no inductor or resistance between the antenna and > earth it can develop wind or snow induced static voltage buildup, which can > lead to discharges that will cause noise in the receiver. Static voltages > can also damage any inline preamps between the vertical and receiver. > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
A drain resistor would be advisable if there is no DC return path to earth... if there is no inductor or resistance between the antenna and earth it can develop wind or snow induced static voltage buildup, which can lead to discharges that will cause noise in the receiver. Static voltages can also damage any inline preamps between the vertical and receiver. Pete _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
Exactly. This has been discussed at length here in the past. Here are a couple of relevant threads: lists.contesting.com/archives//html/Topband/2018-12/msg00192.html lists.contesting.com/archives//html/Topband/2008-11/msg00162.html These are all I could find, after extensive searching. The archives search function here does not seem to work as well as in the past. 73, Mike www.w0btu.com On Wed, Dec 19, 2018, 12:30 PM Chuck Dietz wrote: > The choke bleeds off static charges that accumulate on the vertical. While > I have witnessed noise from huge static charging to a 32 foot vertical > mounted on the roof of the engineering building at Texas Tech in West > Texas, the choke does not bleed off “noise”. Noise is radio frequency > emissions from noise sources which can be local or distant. > > Chuck W5PR > > On Wed, Dec 19, 2018 at 12:19 PM Jamie WW3S wrote: > > > Since verticals are know to be "noisy" on receive, and a fix is a rf > choke > > or bleeder resistor to ground, anyone try that on short verticals used > for > > receive only to quiet some noise? > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
I put resistors (always 100k or more) across EVERY feedline - at the antenna. I keep a chart of what antenna has which value resistor. Two reasons for the chart.. if the resistor changes value, I can find it quickly. IF I drop a coax into a couple others, I can quickly determine which antenna is connected with which feeder. The resistors are all under 2 watt. Since I generally run qrp, the summertime "missing" resistor, leads me to believe "there went another strike".. and the discolored ones, make me believe that even at 2 watts, the wind static has power. Have a great day, Dale - WC7S in Wy "Actions speak louder than words" From: Topband on behalf of Gary - K7EK via Topband Sent: Friday, December 21, 2018 8:11 AM To: Mike Waters Cc: topband Subject: Re: Topband: choke/bleeder resistor on RXvertical? Question about the use of Ohmite bleeder resistors: What are the considerations relative to power rating in this application? Would a 2w OX or OY ceramic resistor survive extended use of full legal amateur power limit on such modes as RTTY, FT8, JT65A, SSTV, and various other high duty cycle digital modes, and AM voice, etc? Best regards, Gary, K7EK Sent from BlueMail On Dec 19, 2018, 13:08, at 13:08, Mike Waters wrote: >ALL my antennas have Ohmite OX or OY resistors from the antenna to >ground. >From 56k to a megohm or three. Doesn't everybody? :-) > >Ditto at dipole feedpoints. > >73, Mike >www.w0btu.com<http://www.w0btu.com> > >On Wed, Dec 19, 2018, 12:19 PM Jamie WW3S >wrote: > >> Since verticals are know to be "noisy" on receive, and a fix is a rf >choke >> or bleeder resistor to ground, anyone try that on short verticals >used for >> receive only to quiet some noise? >> _ >> Searchable Archives: http://www.contesting.com/_topband - Topband >> Reflector >> >_ >Searchable Archives: http://www.contesting.com/_topband - Topband >Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
Question about the use of Ohmite bleeder resistors: What are the considerations relative to power rating in this application? Would a 2w OX or OY ceramic resistor survive extended use of full legal amateur power limit on such modes as RTTY, FT8, JT65A, SSTV, and various other high duty cycle digital modes, and AM voice, etc? Best regards, Gary, K7EK Sent from BlueMail On Dec 19, 2018, 13:08, at 13:08, Mike Waters wrote: >ALL my antennas have Ohmite OX or OY resistors from the antenna to >ground. >From 56k to a megohm or three. Doesn't everybody? :-) > >Ditto at dipole feedpoints. > >73, Mike >www.w0btu.com > >On Wed, Dec 19, 2018, 12:19 PM Jamie WW3S >wrote: > >> Since verticals are know to be "noisy" on receive, and a fix is a rf >choke >> or bleeder resistor to ground, anyone try that on short verticals >used for >> receive only to quiet some noise? >> _ >> Searchable Archives: http://www.contesting.com/_topband - Topband >> Reflector >> >_ >Searchable Archives: http://www.contesting.com/_topband - Topband >Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
Noise is signal spread over a large bandwidth, We tune our receivers to a frequency to copy signals in a relatively narrow bandwidth. Nevertheless, there is some of that noise in that same bandwidth. How does placing a resistor or choke to ground reduce the noise while not reducing the signal at the same time? Wes N7WS On 12/19/2018 11:19 AM, Jamie WW3S wrote: Since verticals are know to be "noisy" on receive, and a fix is a rf choke or bleeder resistor to ground, anyone try that on short verticals used for receive only to quiet some noise? _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
Hi Jamie, I assume you are referring to short RX verticals similar to those used in the Hi-Z and other arrays with a 20 to 25 ft vertical element. I have extensive experience with these and have the HiZ-8 on 160, the passive BSEF-8 array with 25 ft "umbrella" verticals on both 160 and 80 meters and also have the YCCC 9 vertical array. I have never experienced a situation where I believed there was a need for any type of choke or bleeder resistor to quiet noise. As Tree has pointed out with an active array such as the HiZ or YCCC-9 this may create issues with the array amplifiers After a proper installation to ensure good RF connections in the system and address any common mode noise condition that may exist, all of these are extremely quite at my QTH without the need for "bleeder" components. 73 Joel W5ZN On 2018-12-19 11:19, Jamie WW3S wrote: Since verticals are know to be "noisy" on receive, and a fix is a rf choke or bleeder resistor to ground, anyone try that on short verticals used for receive only to quiet some noise? _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
ALL my antennas have Ohmite OX or OY resistors from the antenna to ground. >From 56k to a megohm or three. Doesn't everybody? :-) Ditto at dipole feedpoints. 73, Mike www.w0btu.com On Wed, Dec 19, 2018, 12:19 PM Jamie WW3S wrote: > Since verticals are know to be "noisy" on receive, and a fix is a rf choke > or bleeder resistor to ground, anyone try that on short verticals used for > receive only to quiet some noise? > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
thanks, makes sense.thats why I asked - Original Message - From: "Chuck Dietz" To: "Jamie WW3S" Cc: "Topband" Sent: Wednesday, December 19, 2018 1:29:40 PM Subject: Re: Topband: choke/bleeder resistor on RXvertical? The choke bleeds off static charges that accumulate on the vertical. While I have witnessed noise from huge static charging to a 32 foot vertical mounted on the roof of the engineering building at Texas Tech in West Texas, the choke does not bleed off “noise”. Noise is radio frequency emissions from noise sources which can be local or distant. Chuck W5PR On Wed, Dec 19, 2018 at 12:19 PM Jamie WW3S < w...@zoominternet.net > wrote: Since verticals are know to be "noisy" on receive, and a fix is a rf choke or bleeder resistor to ground, anyone try that on short verticals used for receive only to quiet some noise? _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
At least for the Hi-Z verticals - you can measure a DC voltage when they are active on the antenna against ground. You would not want to short that to ground with a choke!! By having a voltage there - I think you can assume any static DC charges will be quickly dealt with. Essentially a resistor to ground is already there. Tree N6TR On Wed, Dec 19, 2018 at 10:30 AM Chuck Dietz wrote: > The choke bleeds off static charges that accumulate on the vertical. While > I have witnessed noise from huge static charging to a 32 foot vertical > mounted on the roof of the engineering building at Texas Tech in West > Texas, the choke does not bleed off “noise”. Noise is radio frequency > emissions from noise sources which can be local or distant. > > Chuck W5PR > > On Wed, Dec 19, 2018 at 12:19 PM Jamie WW3S wrote: > > > Since verticals are know to be "noisy" on receive, and a fix is a rf > choke > > or bleeder resistor to ground, anyone try that on short verticals used > for > > receive only to quiet some noise? > > _ > > Searchable Archives: http://www.contesting.com/_topband - Topband > > Reflector > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: choke/bleeder resistor on RXvertical?
The choke bleeds off static charges that accumulate on the vertical. While I have witnessed noise from huge static charging to a 32 foot vertical mounted on the roof of the engineering building at Texas Tech in West Texas, the choke does not bleed off “noise”. Noise is radio frequency emissions from noise sources which can be local or distant. Chuck W5PR On Wed, Dec 19, 2018 at 12:19 PM Jamie WW3S wrote: > Since verticals are know to be "noisy" on receive, and a fix is a rf choke > or bleeder resistor to ground, anyone try that on short verticals used for > receive only to quiet some noise? > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
