| Index | Thread | Archive | May-2000 | Archive | Send |
 |
  |
|
   |
|
  |
|
>From: "Natan Huffman" <nhuffman@twcny.rr.com> >To: "Hank Phillips" <aa4hp@titustek.com> >Subject: Re: [Force 12 Talk] C-31XR 15-Meter SWR Measurements >Date: Mon, 15 May 2000 13:27:38 -0400 >X-Mailer: Microsoft Outlook Express 5.00.2919.6600 >X-Loop-Detect: 1 > Natan, Yes, the spacer appears to act as the fulcrum for that motion. My old Alpha 77 doesn't have any grid trip circuit, so I have to increase the loading to keep the grid current excursions down to something tolerable. If additional spacers are an answer, what installation precautions should be observed? Thanks, Hank AA4HP >Hank, > > >From what you are saying, can I assume the movement is past the spacer on >the 20 meter element. > >Natan W6XR >Force 12 East >Ithaca, NY >FN12sk >force12@qth.com >----- Original Message ----- >From: "Hank Phillips" <aa4hp@titustek.com> >To: <Force12Talk@qth.com> >Sent: Monday, May 15, 2000 12:40 PM >Subject: [Force 12 Talk] C-31XR 15-Meter SWR Measurements > > > > I guess from the questions coming back, this isn't a very common > > problem. But I'll try to answer given the instrumentation limits (i.e. no > > anemometer). > > > > When the wind is perfectly calm, I measure 1.4:1 on the Nye Viking meter >in > > the shack on 21.300. At wind speeds under 20 MPH (my best guess), the SWR > > varies from 1.2:1 to 2.2:1 with a period of 2 to 3 seconds which > > corresponds directly with the observed element motion and spacing >variation > > of the driven elements (15/20 meter elements). On really windy days, it's > > worse in direct proportion to the wind speed. > > > > Because of the horrendous lightning in Florida, I don't play with antennas > > much in the rain. > > > > The antenna is essentially flat at 21.150 , rising to about 3:1 at 21.450 > > and 1.3:1 at 21.000. We made no attempt to trim elements at install time, > > just played with the parallel wire feed lines and hairpin coil to minimize > > SWR on 15 and 20. Other bands are not affected by wind. > > > > Tnx es 73, > > > > Hank > > AA4HP > > > > > > > > -------------------------------------------- > > Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. > > Force 12 Web site: http://www.qth.com/force12 > > > > Submissions: send to Force12Talk@qth.com > > To unsubscribe: send a blank e-mail to Force12Talk-leave@qth.com > > Force12Talk Message Archive: http://www.qth.com/force12/list/force12talk > > For problems with the list, contact force12@qth.com > > > > > > -------------------------------------------- Force12Talk mailing list provided as a service by Force 12 Antennas, Inc. Force 12 Web site: http://www.qth.com/force12 Submissions: send to Force12Talk@qth.com To unsubscribe: send a blank e-mail to Force12Talk-leave@qth.com Force12Talk Message Archive: http://www.qth.com/force12/list/force12talk For problems with the list, contact force12@qth.com |
This Thread
|
This Author (May-2000)
|