X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Thu, 24 Aug 2006 19:46:02 -0400 Message-ID: X-Original-Return-Path: Received: from imo-d05.mx.aol.com ([205.188.157.37] verified) by logan.com (CommuniGate Pro SMTP 5.1c.3) with ESMTP id 1347314 for lml@lancaironline.net; Thu, 24 Aug 2006 17:43:30 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.157.37; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-d05.mx.aol.com (mail_out_v38_r7.6.) id q.425.1520bb00 (32913) for ; Thu, 24 Aug 2006 17:35:59 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: <425.1520bb00.321f75bf@aol.com> X-Original-Date: Thu, 24 Aug 2006 17:35:59 EDT Subject: Re: [LML] Re: VHF feedback X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1156455359" X-Mailer: 9.0 Security Edition for Windows sub 5330 X-Spam-Flag: NO -------------------------------1156455359 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en =20 In a message dated 8/24/2006 12:36:33 P.M. Central Standard Time, =20 domcrain@tpg.com.au writes: Scott, me ol=E2=80=99 China, Yep EVERYBODY gets the squeal =E2=80=93 and co= mplains =E2=80=9CCZJ =E2=80=93=20 ya got a loud background squeal in yer transmission!!!=E2=80=9D Dom, =20 Oh, so glad I went back and read your first transmission with understanding= .=20 I guess the squeal was blocking me wee brain out. =20 Let's see, it shouldn't be caused by any wiring of the PTT since that is =20 usually just a switch making to ground (unless the ground is not a good one= ). =20 The radio can produce a side tone so that you can hear yourself talk and be=20= =20 reassured that someone else would be able to hear you, too. An intercom ca= n=20 also produce such a side tone back to your headsets (listening to yourself =20 over the intercom, just like your unfortunate passenger. Neither of these =20 should be a problem with a transmission unless the vox operated intercom giv= es =20 you a squeal without touching the transmit key. =20 Hmmmm, this seems isolated to the mike circuit, but only when the intercom =20 is on............... Hmmmmm.. Wired by an avionics shop, eh? =20 I wonder if both side tones are in conflict? Have you tried to make sure=20 the headset cannot feed the mike when transmitting with the intercom on - i= .e.=20 remove the plugs for the passenger side, make sure the mike opening is faci= ng=20 your mouth (not pointing at the ear piece) and cover it somewhat with hand=20= -=20 or completely with your hand and see if your buddy, around the corner with=20 the handheld, hears a squeal when tx but no voice. In other words, can you= =20 check this on the ground without the engine running by using another radio.= =20 =20 Try to isolate this condition even more. Have you swapped headsets from=20 side to side? Make sure you turn off the other radio also since there can=20= be=20 problems if they are tuned to the same freq and/or they share an antenna =20 without a transmit isolator. =20 Scott =20 PS: My GSM phone (RAZR) can cause noise in audio circuits, but it is just=20 annoying, not a squeal. I shut the sucker off when I fly. -------------------------------1156455359 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en
In a message dated 8/24/2006 12:36:33 P.M. Central Standard Time,=20 domcrain@tpg.com.au writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3D"Times New Roman" color=3D#= 0000ff=20 size=3D3>Scott, me ol=E2=80=99 China, Yep EVERYBODY gets= the=20 squeal =E2=80=93 and complains =E2=80=9CCZJ =E2=80=93 ya got a loud backgr= ound squeal in yer=20 transmission!!!=E2=80=9D
Dom,
 
Oh, so glad I went back and read your first transmission with=20 understanding.  I guess the squeal was blocking me wee=20 brain out.
 
Let's see, it shouldn't be caused by any wiring of the PTT since that i= s=20 usually just a switch making to ground (unless the ground is not a= =20 good one).
 
The radio can produce a side tone so that you can hear yourself talk an= d be=20 reassured that someone else would be able to hear you, too.  An interco= m=20 can also produce such a side tone back to your headsets (listening to yourse= lf=20 over the intercom, just like your unfortunate passenger.  Neither of th= ese=20 should be a problem with a transmission unless the vox operated intercom giv= es=20 you a squeal without touching the transmit key.
 
Hmmmm, this seems isolated to the mike circuit, but only when the inter= com=20 is on............... Hmmmmm..  Wired by an avionics shop, eh?
 
I wonder if both side tones are in conflict?  Have you tried to ma= ke=20 sure the headset cannot feed the mike when transmitting with the intercom=20 on - i.e. remove the plugs for the passenger side, make sure the mike=20 opening is facing your mouth (not pointing at the ear piece) and cover=20= it=20 somewhat with hand - or completely with your hand and see if your buddy, aro= und=20 the corner with the handheld, hears a squeal when tx but no voice.  In=20 other words, can you check this on the ground without the engine running by=20 using another radio. 
 
Try to isolate this condition even more.  Have you swapped headset= s=20 from side to side?  Make sure you turn off the other radio also since t= here=20 can be problems if they are tuned to the same freq and/or they share an ante= nna=20 without a transmit isolator.
 
Scott
 
PS: My GSM phone (RAZR) can cause noise in audio circuits, but it=20= is=20 just annoying, not a squeal.  I shut the sucker off when I=20 fly.
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