Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dc05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 4BA1B380000AD; Wed, 27 Jun 2012 11:54:52 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SjuZC-00023v-Di for rs_out_1@blacksheep.org; Wed, 27 Jun 2012 16:54:06 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SjuZB-00023m-Qm for rsgb_lf_group@blacksheep.org; Wed, 27 Jun 2012 16:54:05 +0100 Received: from out1.ip07ir2.opaltelecom.net ([62.24.128.243]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1SjuZ9-0005k9-QG for rsgb_lf_group@blacksheep.org; Wed, 27 Jun 2012 16:54:04 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ag0FAIIr609Ok8wX/2dsb2JhbABFgkWeBZVdgQiCEwUBAQUIAQEDSQIPHQEBAwUCAQMRBAEBCiUUAQQaBhYIBhMKAQICAQGHbAMPsCILiVCKVGMVBoVvA4gXhTaSaIUAgl+BVw X-IronPort-AV: E=Sophos;i="4.77,485,1336345200"; d="scan'208,217";a="40024939" Received: from host-78-147-204-23.as13285.net (HELO xphd97xgq27nyf) ([78.147.204.23]) by out1.ip07ir2.opaltelecom.net with SMTP; 27 Jun 2012 16:54:02 +0100 Message-ID: <005c01cd547d$0fecba30$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <002801cd536e$76b08400$0401a8c0@xphd97xgq27nyf> <172D1CB5F32F43A790DBC99A73F73D59@AGB> <1340728957.15592.YahooMailNeo@web171601.mail.ir2.yahoo.com> Date: Wed, 27 Jun 2012 15:53:57 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.8 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: To enlighten those that do not know. Not so many moons ago 2m es 70 cms was mainly CW and AM then SSB as well and FM was used only by repeaters when it first arrived. Then for some reason the FM spread to the rest of 2m es 70 cms but there was still a segment at the bottom of each band for cw es ssb, mainly used for DX contacts. Like you say in the old days it was tuning Hight to Low or vice versa nearly everyone was xtal controlled. The Liner 2 es Liner 430 black boxes came along with vfo es cw es ssb, then simplex became the norm. 4 metres was also AM on 70.26 calling channel. For local chats FM is fine but looking further afield then AM, SSB and CW have more punch and better. The LF/MF operator will also find this info useful. g3kev [...] Content analysis details: (0.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [62.24.128.243 listed in list.dnswl.org] 0.0 FSL_XM_419 Old OE version in X-Mailer only seen in 419 spam -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 FSL_UA FSL_UA 0.8 AXB_XMAILER_MIMEOLE_OL_024C2 AXB_XMAILER_MIMEOLE_OL_024C2 X-Scan-Signature: 974e9bcd09e4f3403f97af2f38f8fb73 Subject: Re: LF: A/G FREQS Content-Type: multipart/alternative; boundary="----=_NextPart_000_0059_01CD547D.0FBCF7A0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,HTML_MESSAGE autolearn=no version=2.63 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-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:453384096:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40854feb2ccc3870 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_0059_01CD547D.0FBCF7A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To enlighten those that do not know. Not so many moons ago 2m es 70 cms = was mainly CW and AM then SSB as well and FM was used only by repeaters = when it first arrived. Then for some reason the FM spread to the rest of = 2m es 70 cms but there was still a segment at the bottom of each band = for cw es ssb, mainly used for DX contacts. Like you say in the old days it was tuning Hight to Low or vice versa = nearly everyone was xtal controlled. The Liner 2 es Liner 430 black = boxes came along with vfo es cw es ssb, then simplex became the norm. 4 = metres was also AM on 70.26 calling channel.=20 For local chats FM is fine but looking further afield then AM, SSB and = CW have more punch and better. The LF/MF operator will also find this info useful. g3kev ----- Original Message -----=20 From: M0FMT=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Tuesday, June 26, 2012 4:42 PM Subject: Re: LF: A/G FREQS Well Graham when I were a Jate we only had one xtal and a QQV02-6 on = 432.00 amplitude modulated on the plate in the good old days. After all = its just the product of mixing two frequencies 432 with audio in a = nonlinear device like a Class C amp works from almost DC to light!. = Nowerdays I guess you would PWM the carrier on the PA gate/ base = producing the same effect and using considerably less power over all. = Class E an all. 73 es GL Pete M0FMT IO91UX From: Graham To: rsgb_lf_group@blacksheep.org=20 Sent: Tuesday, 26 June 2012, 17:09 Subject: Re: LF: A/G FREQS Steady on Mal ! this is getting technical !" Your right , FM has a cut off point , where demodulation fails = and also a capture effect , where the stronger of 2 signals will = acquire and hold the demodulator ..always fun on 2 mtrs when a = mobile suddenly takes the channel=20 Am has no cut off point , but gradual degradation until the = recovered audio is no longer usable ......eg, mcw would readable = much lower than AM speech=20 I think much over 250/300 MHz its actually not possible to = produce AM , could be wrong , but there is a limit , may be by = high level modulation falls over , dont see why could not be = via transverting .......=20 G.. From: mal hamilton=20 Sent: Tuesday, June 26, 2012 8:36 AM To: rsgb=20 Subject: LF: A/G FREQS As stated Air/Ground vhf/uhf is AM and simplex working. I have also = noticed a well modulated AM transmitter is more potent than a FM = transmitter when working at max range. On AM the RX bandwidth can be = opened up to receive several stations simultaneously then select the one = of interest by closing down the selectivity, the same applies on CW. On = FM if you tried this the transmission would fall into a black hole, in = other words the FM rx has to be tailored to the exact bandwidth of the = transmission (same deviation value) g3kev ------=_NextPart_000_0059_01CD547D.0FBCF7A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
To enlighten those that do not know. Not so many = moons ago=20 2m es 70 cms was mainly CW and AM then SSB as well and FM was used only = by=20 repeaters when it first arrived. Then for some reason the FM spread to = the rest=20 of 2m es 70 cms but there was still a segment at the bottom of each band = for cw=20 es ssb, mainly used for DX contacts.
Like you say in the old days it was tuning Hight = to Low or=20 vice versa nearly everyone was xtal controlled. The Liner 2 es Liner 430 = black=20 boxes came along with vfo es cw es ssb, then simplex became the norm. 4 = metres=20 was also AM on 70.26 calling channel.
For local chats FM is fine but looking further = afield then=20 AM, SSB and CW have more punch and better.
The LF/MF operator will also find this info=20 useful.
g3kev
 
 
----- Original Message -----
From:=20 M0FMT
Sent: Tuesday, June 26, 2012 = 4:42=20 PM
Subject: Re: LF: A/G = FREQS

Well Graham when I were a Jate we only had one xtal and a QQV02-6 = on=20 432.00 amplitude modulated on the plate in the good old days. = After all=20 its just the product of mixing two frequencies 432 with audio in = a=20 nonlinear device like a Class C amp works from almost DC to light!. = Nowerdays=20 I guess you would PWM the carrier on the PA gate/ base producing the = same=20 effect and using considerably less power over all. Class E an = all.
73 es GL Pete M0FMT IO91UX
From:=20 Graham <g8fzk@g8fzk.fsnet.co.uk>
To: = rsgb_lf_group@blacksheep.org=20
Sent: Tuesday, 26 = June 2012,=20 17:09
Subject: Re: = LF: A/G=20 FREQS

Steady on Mal !   this  is getting  = technical =20 !"
 
Your  right  , FM has a  cut off  point  = ,=20 where  demodulation fails  and  also  a =20 capture  effect , where the  stronger of  2 = signals =20 will  acquire  and  hold the  demodulator=20 ..always   fun  on 2  mtrs   when = a =20 mobile  suddenly  takes  the  channel
 
Am  has no  cut off  point , but  = gradual =20 degradation  until the  recovered  audio  is = no =20 longer usable  ......eg,  mcw  would  = readable =20 much  lower  than  AM speech
 
I think  much over  250/300 MHz   its =20 actually  not  possible to  produce  AM  , = could=20 be  wrong  , but  there is a  limit  ,=20 may   be  by  high  level  modulation = falls over=20 , dont  see  why  could  not  be  = via =20 transverting  .......
 
G..
From: mal hamilton
Sent: Tuesday, June 26, 2012 8:36 AM
To: rsgb
Subject: LF: A/G FREQS

As stated Air/Ground vhf/uhf is AM and=20 simplex working.  I have also noticed a well modulated AM=20 transmitter is more potent than a FM transmitter when working at max = range. On=20 AM the RX bandwidth can be opened up to receive several stations=20 simultaneously then select the one of interest by closing down the=20 selectivity, the same applies on CW.  On FM if you tried this=20 the transmission would fall into a black hole, in other words = the FM=20 rx has to be tailored to the exact bandwidth of the transmission = (same=20 deviation value)
g3kev
 


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