Return-Path: X-Spam-DCC: paranoid 1102; Body=3 Fuz1=3 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_40_50,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 t9EKeSti009996 for ; Wed, 14 Oct 2015 22:40:29 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZmSnq-0007TG-Cx for rs_out_1@blacksheep.org; Wed, 14 Oct 2015 21:37:38 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZmSnq-0007T7-2B for rsgb_lf_group@blacksheep.org; Wed, 14 Oct 2015 21:37:38 +0100 Received: from mail-wi0-f172.google.com ([209.85.212.172]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1ZmSmp-0000OV-HH for rsgb_lf_group@blacksheep.org; Wed, 14 Oct 2015 21:37:36 +0100 Received: by wicgb1 with SMTP id gb1so794144wic.1 for ; Wed, 14 Oct 2015 13:36:20 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=A/2TRlGal/ikVGgERvDTGHZbKlBm+4vTJkgGVots6Is=; b=yKtNRBSBHmPvBlyvqyo0dd5kDpQtFXyToD7zGXNt7ndtJ4v6ycNa/AL2ChHAGtqYzc zHTcZj7KzEN98i+PvohryxYCWopr8CzLwAwuyQLPZPwX4Y8Mg454vgTltGtjgGiVHdNZ Fmq0o73JKkDdxGSGz8Bbll2tL25Zp2pBTN94gQlL5S0zCMOPXc6nri06FL8OAVkoZCuT WrPugd8gauTJdjPy8HWFf6VKag7CAHnl7Feq8lX05XnyzbWSl9RYjLKbPfzzGUj68u5d Vs1S2MJaVQPueFhM73sL9RwuhicghHhPjDzaQP3BmoEKWYIlUWAvjXDaLlUhLLIFes39 UlxQ== MIME-Version: 1.0 X-Received: by 10.180.87.6 with SMTP id t6mr28449034wiz.20.1444854980291; Wed, 14 Oct 2015 13:36:20 -0700 (PDT) Received: by 10.28.47.212 with HTTP; Wed, 14 Oct 2015 13:36:20 -0700 (PDT) In-Reply-To: References: <1821006912.20151014193718@chriswilson.tv> Date: Wed, 14 Oct 2015 21:36:20 +0100 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Scan-Signature: e6360f34ef88d0e1db765f70efb2bfe9 Subject: Re: LF: PA0RDT antenna near a TX? Front end OK? Content-Type: multipart/alternative; boundary=f46d0444ec07da30fa0522168342 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: 4385 --f46d0444ec07da30fa0522168342 Content-Type: text/plain; charset=UTF-8 My Procomm AAC-1 , when sitting under the 137kHz antenna with 700 Watts feeding it (ie. about 7metres away at the shortest distance) , delivers a clipped waveform of 6V pk=pk into a 50 ohm load. About +20dBm. The SDR I/Q objects and complains forcibly by flashing its red overload led, but it can survive that sort of level. Any receiver that can't survive 100mW on its input is best put out of its misery, anyway. 'jnt On 14 October 2015 at 21:24, Michael Sapp wrote: > Laurence, Chris & All: I did a test with my eprobe which is about 30 feet > away from my HF elevated ground plane that has 65 ft radials a few years > back. With 100W output on 40 meters. I was getting 1mw of RF power from the > eprobe into a Boonton RF voltmeter. I was using a 1 inch wide by 12 inch > long brass strip as the eprobe antenna at the time. I would assume the > eprobe may be able to generate more power than that at higher nearby > transmitter power levels. Suitable overload protection for a receiver front > end would appear to be prudent..... > > 73, Mike wa3tts > > > > ----- Original Message ----- > *From:* Laurence KL7 L > *To:* rsgb_lf_group@blacksheep.org > *Sent:* Wednesday, October 14, 2015 2:56 PM > *Subject:* RE: LF: PA0RDT antenna near a TX? Front end OK? > > Chris > > I run up to 1Kw on 136kHz and up to 400W on 475kHz and "alive" Eprobes > (L400 and PA0RDT variants) about 100-150ft away up at 30ft plus and not > blown them up. They don't like it much of course and produce unwanted > products during Tx but that not surprising. > > Only FET failure to date has been down in Oklahoma from a nearby lightning > strike. > > > Laurence > KL7L et al > > > > > > > If I mount my PA0RDT clone on my mast stub, about 50 feet from my LF > > TX'ing aerial, is it likely to be damaged if powered on when TX'ing? > > > > Thanks. > > > Best regards, > > Chris mailto:chris@chriswilson.tv > > > > > > --f46d0444ec07da30fa0522168342 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
My Procomm AAC-1 , when sitting under the 137kHz =C2=A0ant= enna with 700 Watts feeding it (ie. about 7metres away at the shortest dist= ance) , delivers a clipped waveform of 6V pk=3Dpk into a 50 ohm load. =C2= =A0 About +20dBm. =C2=A0=C2=A0

The SDR I/Q objects and c= omplains forcibly by flashing its red overload led, but it can survive that= sort of level.=C2=A0 Any receiver that can't survive =C2=A0100mW on it= s input is best put out of its misery, anyway.

= 9;jnt


On 14 October 2015 at 21:24, Michael Sapp <wa3tts@verizo= n.net> wrote:
Laurence, Chris & All:=C2=A0 I did= a test with=20 my eprobe which is about 30 feet away from my HF elevated ground plane that= has=20 65 ft radials a few years back. With 100W output on 40 meters. I was gettin= g 1mw=20 of RF power from the eprobe into a Boonton RF voltmeter. I was using a 1 in= ch=20 wide=C2=A0by 12 inch long brass strip as the eprobe antenna at the time.=C2= =A0 I=20 would assume the eprobe may be able to generate more power than that at hig= her=20 nearby transmitter power levels.=C2=A0Suitable overload protection for a=20 receiver front end would appear to be prudent.....
=C2=A0
73, Mike wa3tts
=C2=A0
=C2=A0
----- Original Message -----
From:=20 Laurence KL7 L
Sent: Wednesday, October 14, 2015 2= :56=20 PM
Subject: RE: LF: PA0RDT antenna nea= r a=20 TX? Front end OK?

Chris
=C2=A0
I run=C2=A0up to 1Kw on 136kHz and up= to 400W=20 on 475kHz=C2=A0and "alive"=C2=A0Eprobes (L400 and PA0RDT varian= ts) about=20 100-150ft away up at 30ft plus=C2=A0and not blown them up. They don't= like it=20 much of course and produce unwanted products during Tx but that not=20 surprising.
=C2=A0
Only FET failure to date has been down in Oklaho= ma=20 from a nearby lightning strike.
=C2=A0
=C2=A0
Laurence
KL7L e= t=20 al
=C2=A0
>
>
> If I mount my PA0RDT clone on my mast stub, ab= out=20 50 feet from my LF
> TX'ing aerial, is it likely to be damaged = if=20 powered on when TX'ing?
>
> Thanks.

> Best=20 regards,
> Chris mailto:chris@chriswilson.tv
>
>=20

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