Re: Antenna Setup For HF
"louis skamangas [email protected] [VR-500]" <[email protected]> Tue, 3 May 2016 02:31:05 +0000 (UTC)
| Newsgroups | gmane.recreation.radio.hardware.yaesu.vr-500 |
|---|---|
| Message-ID | <[email protected]> |
--rHrpMNmIrA6DtQSCkbvOcMPG31yhMgBBy00JPoa Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable I've tried making a few small portable antennas for my vr-500. All have wor= ked better than the stock antenna for HF (they would almost have to), but o= ften worse at VHF and above. Here are a few things I've tried: 1. A telesc= opic whip, a couple of feet or so in length, with a small toroidal transfor= mer in between the antenna and BNC connector. The core I used was a black c= ore about 3/8" in diameter (material unknown, I just used what I had on han= d). I don't remember the exact number of turns, but I believe it was 4 or 5= on the radio side and around 20 on the antenna side. The two windings have= a common connection that goes to the outer conductor of the BNC connector.= I found that this antenna gives an audible improvement in reception across= the entire HF spectrum except around 8 MHz, for some reason. It also impro= ved reception on much of the broadcast band. 2. A rubber duckie antenna, = originally a clamp-on antenna for CB walkie-talkies, with the original load= ing coil removed. In place of the coil, I put a series string of about 10 d= ifferent inductors, along with a DIP switch that can short any of the induc= tors independently of the others, allowing many different combinations of i= nductors. This is, in effect, a variable loading coil that resonates the an= tenna to numerous frequencies throughout the HF spectrum. Sorry, but I don'= t remember the inductor values, but they were all different and were determ= ined through trial and error. This seems to work considerably better than t= he above antenna, but requires flipping switches when you change frequency.= 3. A small active-antenna-type amplifier between a telescopic whip or duc= kie. I wasn't too impressed with the performance, but I ran the amp on less= voltage than it normally uses. I plan to try it again using a 6-volt batte= ry about the size of an N-cell to keep the size down, All three antennas = were designed to give a better match between the (nominal) 50-ohm input of = the radio and the very high impedance of any short portable antenna at HF f= requencies. Hope this helps. Lou -----------------------------------------= --- On Mon, 5/2/16, [email protected] [VR-500] <[email protected]> w= rote: I have tried various bnc adapters for HF/SSB listening, using ra= ndom wire as an antenna. =C2=A0What is the best antenna for shortwave, con= sidering portability and not getting something "too good" so it overloads= . --rHrpMNmIrA6DtQSCkbvOcMPG31yhMgBBy00JPoa Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/htm= l4/strict.dtd"> <html> <head> </head> =20 <body style=3D"background-color: #fff;"> <span style=3D"display:none"> </span> <!--~-|**|PrettyHtmlStartT|**|-~--> <div id=3D"ygrp-mlmsg" style=3D"position:relative;"> <div id=3D"ygrp-msg" style=3D"z-index: 1;"> <!--~-|**|PrettyHtmlEndT|**|-~--> <div id=3D"ygrp-text" > =20=20=20=20=20=20 =20=20=20=20=20=20 <p>I've tried making a few small portable antennas for my vr-500.= All have worked better than the stock antenna for HF (they would almost ha= ve to), but often worse at VHF and above. Here are a few things I've tr= ied:<br> <br> 1. A telescopic whip, a couple of feet or so in length, with a small toroid= al transformer in between the antenna and BNC connector. The core I used wa= s a black core about 3/8" in diameter (material unknown, I just used w= hat I had on hand). I don't remember the exact number of turns, but I b= elieve it was 4 or 5 on the radio side and around 20 on the antenna side. T= he two windings have a common connection that goes to the outer conductor o= f the BNC connector. I found that this antenna gives an audible improvement= in reception across the entire HF spectrum except around 8 MHz, for some r= eason. It also improved reception on much of the broadcast band. <br> <br> 2. A rubber duckie antenna, originally a clamp-on antenna for CB walkie-tal= kies, with the original loading coil removed. In place of the coil, I put a= series string of about 10 different inductors, along with a DIP switch tha= t can short any of the inductors independently of the others, allowing many= different combinations of inductors. This is, in effect, a variable loadin= g coil that resonates the antenna to numerous frequencies throughout the HF= spectrum. Sorry, but I don't remember the inductor values, but they we= re all different and were determined through trial and error. This seems to= work considerably better than the above antenna, but requires flipping swi= tches when you change frequency.<br> <br> 3. A small active-antenna-type amplifier between a telescopic whip or ducki= e. I wasn't too impressed with the performance, but I ran the amp on le= ss voltage than it normally uses. I plan to try it again using a 6-volt bat= tery about the size of an N-cell to keep the size down, <br> <br> All three antennas were designed to give a better match between the (nomina= l) 50-ohm input of the radio and the very high impedance of any short porta= ble antenna at HF frequencies. Hope this helps.<br> <br> Lou<br> --------------------------------------------<br> On Mon, 5/2/16, [email protected] [VR-500] <[email protected]>= wrote:<br> <br> I have tried various bnc adapters for HF/SSB<br> listening, using random wire as an antenna. =C2=A0What is<br> the best antenna for shortwave, considering portability and<br> not getting something "too good" so it<br> overloads.<br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> </p> </div> =20=20=20=20=20 <!--~-|**|PrettyHtmlStart|**|-~--> <div style=3D"color: #fff; height: 0;">__._,_.___</div> =20=20=20=20=20=20=20=20=20=20 =20=20 =20 =20=20=20=20 <div style=3D"clear:both"> </div> <div id=3D"fromDMARC" style=3D"margin-top: 10px;"> <hr style=3D"height:2px ; border-width:0; color:#E3E3E3; background= -color:#E3E3E3;"> Posted by: louis skamangas <[email protected]> <hr = style=3D"height:2px ; border-width:0; color:#E3E3E3; background-color:#E3E3= E3;"> </div> <div style=3D"clear:both"> </div> <table cellspacing=3D4px style=3D"margin-top: 10px; margin-bottom: 10px= ; color: #2D50FD;"> <tbody> <tr> <td style=3D"font-size: 12px; font-family: arial; font-weight: bo= ld; padding: 7px 5px 5px;" > <a style=3D"text-decoration: none; color: #2D50FD= " href=3D"https://groups.yahoo.com/neo/groups/VR-500/conversations/messages= /3720;_ylc=3DX3oDMTJvZGE1NnIyBF9TAzk3MzU5NzE0BGdycElkAzE3Mjk4NwRncnBzcElkAz= E3MDUwNjMxMDgEbXNnSWQDMzcyMARzZWMDZnRyBHNsawNycGx5BHN0aW1lAzE0NjI3MTg3MjA-?= act=3Dreply&messageNum=3D3720">Reply via web post</a> </td> <td>•</td> <td style=3D"font-size: 12px; font-family: arial; padding: 7px 5p= x 5px;" > <a href=3D"mailto:[email protected]?subject=3DRe%3A%20%5BVR-= 500%5D%20Antenna%20Setup%20For%20HF" style=3D"text-decoration: none; color:= #2D50FD;"> Reply to sender </a> </td> <td>•</td> <td style=3D"font-size: 12px; font-family: arial; padding: 7px 5p= x 5px;"> <a href=3D"mailto:[email protected]?subject=3DRe%3A%20%5BV= R-500%5D%20Antenna%20Setup%20For%20HF" style=3D"text-decoration: none; colo= r: #2D50FD"> Reply to group </a> </td> <td>•</td> <td style=3D"font-size: 12px; font-family: arial; padding: 7px 5p= x 5px;" > <a href=3D"https://groups.yahoo.com/neo/groups/VR-500/conversat= ions/newtopic;_ylc=3DX3oDMTJkcTlxMmowBF9TAzk3MzU5NzE0BGdycElkAzE3Mjk4NwRncn= BzcElkAzE3MDUwNjMxMDgEc2VjA2Z0cgRzbGsDbnRwYwRzdGltZQMxNDYyNzE4NzIw" style= =3D"text-decoration: none; color: #2D50FD">Start a New Topic</a> </td> <td>•</td> <td style=3D"font-size: 12px; font-family: arial; padding: 7px 5p= x 5px;color: #2D50FD;" > <a href=3D"https://groups.yahoo.com/neo/groups/= VR-500/conversations/topics/3719;_ylc=3DX3oDMTMzc2FlYm9tBF9TAzk3MzU5NzE0BGd= ycElkAzE3Mjk4NwRncnBzcElkAzE3MDUwNjMxMDgEbXNnSWQDMzcyMARzZWMDZnRyBHNsawN2dH= BjBHN0aW1lAzE0NjI3MTg3MjAEdHBjSWQDMzcxOQ--" style=3D"text-decoration: none;= color: #2D50FD;">Messages in this topic</a> (3) </td> </tr> </tbody> </table> =20=20=20=20=20=20=20=20 <!------- Start Nav Bar ------> <div id=3D"ygrp-grfd" style=3D"font-family: Verdana; font-size: 12px; p= adding: 15px 0;"> =20=20=20=20=20=20 <!-- |**|begin egp html banner|**| --> Post message: VR-500@= yahoogroups.com <BR> Subscribe:  = ; [email protected] <BR> Unsubscribe: VR-500-u= [email protected] <BR> List owner: VR-= [email protected] <BR> <BR> <BR> <BR> <BR> <BR> Ejoy the list!!=20=20=20=20=20=20 <!-- |**|end egp html banner|**| --> </div> =20=20 =20 <!-- |**|begin egp html banner|**| --> <div id=3D"ygrp-vital" style=3D"background-color: #f2f2f2; font-family: Ver= dana; font-size: 10px; margin-bottom: 10px; padding: 10px;"> <span id=3D"vithd" style=3D"font-weight: bold; color: #333; text-transf= orm: uppercase; "><a href=3D"https://groups.yahoo.com/neo/groups/VR-500/inf= o;_ylc=3DX3oDMTJkM244NGVqBF9TAzk3MzU5NzE0BGdycElkAzE3Mjk4NwRncnBzcElkAzE3MD= UwNjMxMDgEc2VjA3Z0bARzbGsDdmdocARzdGltZQMxNDYyNzE4NzIw" style=3D"text-decor= ation: none;">Visit Your Group</a></span> <ul style=3D"list-style-type: none; margin: 0; padding: 0; display: in= line;"> </ul> </div> <div id=3D"ft" style=3D"font-family: Arial; font-size: 11px; margin-top: 5p= x; padding: 0 2px 0 0; clear: both;"> <a href=3D"https://groups.yahoo.com/neo;_ylc=3DX3oDMTJjbTJxMm1oBF9TAzk3Mz= U5NzE0BGdycElkAzE3Mjk4NwRncnBzcElkAzE3MDUwNjMxMDgEc2VjA2Z0cgRzbGsDZ2ZwBHN0a= W1lAzE0NjI3MTg3MjA-" style=3D"float: left;"><img src=3D"http://l.yimg.com/r= u/static/images/yg/img/email/new_logo/logo-groups-137x15.png" height=3D"15"= width=3D"137" alt=3D"Yahoo! 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