Return-Path: X-Spam-DCC: paranoid 1102; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: * X-Spam-Status: No, score=1.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_MUA_OUTLOOK,HTML_MESSAGE autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id t48GVuE3009940 for ; Fri, 8 May 2015 18:31:56 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Yql8M-0002fq-9J for rs_out_1@blacksheep.org; Fri, 08 May 2015 17:28:18 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Yql8L-0002fh-Vc for rsgb_lf_group@blacksheep.org; Fri, 08 May 2015 17:28:17 +0100 Received: from rgout06.bt.lon5.cpcloud.co.uk ([65.20.0.183]) by relay1.thorcom.net with esmtp (Exim 4.85) (envelope-from ) id 1Yql8K-0000kc-8A for rsgb_lf_group@blacksheep.org; Fri, 08 May 2015 17:28:16 +0100 X-OWM-Source-IP: 81.129.180.111(GB) X-OWM-Env-Sender: alan.melia@btinternet.com X-CTCH-RefID: str=0001.0A090205.554CE41F.0025,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-Junkmail-Premium-Raw: score=39/50,refid=2.7.2:2015.5.8.143915:17:39.532,ip=81.129.180.111,rules=__HAS_MSGID, __SANE_MSGID, MSGID_32HEX_LC, INVALID_MSGID_NO_FQDN, __MSGID_32HEX, __HAS_FROM, __PHISH_FROM2, __FRAUD_WEBMAIL_FROM, __TO_MALFORMED_2, __TO_NO_NAME, __REFERENCES, __RUS_SUBJ_ALL_UCASE_1251, __RUS_SUBJ_ALL_UCASE_KOI8R, __BOUNCE_CHALLENGE_SUBJ, __BOUNCE_NDR_SUBJ_EXEMPT, __FRAUD_SUBJ_ALLCAPS, __MIME_VERSION, __CT, __CTYPE_MULTIPART_ALT, __CTYPE_HAS_BOUNDARY, __CTYPE_MULTIPART, __HAS_X_PRIORITY, __HAS_MSMAIL_PRI, __HAS_X_MAILER, USER_AGENT_OE, __OUTLOOK_MUA_1, __USER_AGENT_MS_GENERIC, __ANY_URI, __URI_NO_PATH, __SUBJ_ALPHA_NEGATE, SUPERLONG_LINE, __HAS_HTML, BODYTEXTP_SIZE_3000_LESS, BODY_SIZE_5000_5999, BODYTEXTH_SIZE_10000_LESS, __MIME_HTML, __TAG_EXISTS_HTML, RDNS_GENERIC_POOLED, __URI_NS, SXL_IP_DYNAMIC[111.180.129.81.fur], HTML_50_70, RDNS_SUSP_GENERIC, __PHISH_FROM, __OUTLOOK_MUA, RDNS_SUSP, __FRAUD_WEBMAIL, FORGED_MUA_OUTLOOK, BODY_SIZE_7000_LESS, REFERENCES X-CTCH-Spam: Unknown Received: from gnat (81.129.180.111) by rgout06.bt.lon5.cpcloud.co.uk (8.6.122.06) (authenticated as alan.melia@btinternet.com) id 554CCA2D0003A3CE for rsgb_lf_group@blacksheep.org; Fri, 8 May 2015 17:28:15 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=btcpcloud; t=1431102496; bh=iMxKTb1f05cZRz3CvdUO3bqqeB2HuDZZWNnJ2fm73RM=; h=Message-ID:From:To:References:Subject:Date:MIME-Version:X-Mailer; b=TzwZFJ8e4bQFry+s985fuEsd6RhQUyYqGA5JvwBBhbRflqlHG0CKyivCZfg+poQ28za2w6c8TEnXO10kQMvgjcfKNHDgBNXankZY3uQyVV96wxesfHLkF+xya5WKjKmKAyEtSK56m2df7fBkmmJeoLjEUy/xwjht45T/+3OETFE= Message-ID: <4B2BCE47BD6948849A073E2E814D05A7@gnat> From: "Alan Melia" To: References: Date: Fri, 8 May 2015 17:28:13 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-Scan-Signature: d5ac66e7920295f519efeb68ecc59e6f Subject: LF: Re: UNIPOLE V INV-L ? Content-Type: multipart/alternative; boundary="----=_NextPart_000_0033_01D089B4.5CD69630" X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 3071 This is a multi-part message in MIME format. ------=_NextPart_000_0033_01D089B4.5CD69630 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi G,=20 Well the Laws of Physics dont change however much one might wish it :-)) The unipole will be approx -3dB ERP on the inv L Effective height of unipole approx half physical height Effective height of inv L same height with 1.5*h top is approx 0.9* = physical height inv L disadvantage.....requires another support and insulators inv L advantage ........over poor ground with the same feed-point = grounding the inL will have lower ground loss and higher capacity. Over = good ground or sea-water this advantage may disappear, but losses will = be low anyway. I think this folded monopole is covered in Rik's tutorial, the extra = wires are just "matching" they dont increase the radiation resistance. = Commercial stations like grounded aerials for lightning protection. Alan G3NYK=20 ----- Original Message -----=20 From: Graham=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Friday, May 08, 2015 4:54 PM Subject: LF: UNIPOLE V INV-L ? UNI-POLE V INV-L ? https://www.lbagroup.com/products/tunipole-combipole-antenna-systems Assuming a robust ATU and earth =20 What would be the advantage / disadvantage of say a 40 foot = uni-pole , to a conventional 40 x 60 ft inv L at MF ? tower and side wire or RG8U / copper pipe construction ? = ......... -3 dB of a similar size loop ? 73-Graham G0NBD ------=_NextPart_000_0033_01D089B4.5CD69630 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi G,
Well the Laws of Physics dont change = however much=20 one might wish it :-))
 
The unipole will be approx -3dB ERP on = the inv=20 L
 
Effective height of unipole approx half = physical=20 height
Effective height of inv L same height = with 1.5*h=20 top is approx 0.9* physical height
 
inv L disadvantage.....requires another = support and=20 insulators
inv L advantage ........over poor = ground with the=20 same feed-point grounding the inL will have lower ground loss and higher = capacity. Over good ground or sea-water this advantage may disappear, = but losses=20 will be low anyway.
 
I think this folded monopole is covered = in Rik's=20 tutorial, the extra wires are just "matching" they dont increase the = radiation=20 resistance. Commercial stations like grounded aerials for lightning=20 protection.
 
Alan
G3NYK 
----- Original Message -----
From:=20 Graham
Sent: Friday, May 08, 2015 4:54 = PM
Subject: LF: UNIPOLE V INV-L = ?

UNI-POLE  V  INV-L ?
 
https://www.lbagroup.com/products/tunipole-combipole-antenna-systems=
 
Assuming  a robust   ATU and   earth=20   
 
What would be the  advantage  / = disadvantage  =20 of  say  a   40  foot  uni-pole =20 ,   to  a  conventional     40 = x=20 60   ft  inv L   at  MF ?
 
tower  and  side wire  or   RG8U  / = copper  pipe  construction ? .........  -3 dB  of = a =20 similar size loop  ?
 
73-Graham
G0NBD
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