Return-Path: X-Spam-DCC: paranoid 1002; Body=3 Fuz1=3 Fuz2=3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_MESSAGE,RATWARE_GECKO_BUILD 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 t9NM8v3p013471 for ; Sat, 24 Oct 2015 00:08:57 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZpkSN-0000vs-At for rs_out_1@blacksheep.org; Fri, 23 Oct 2015 23:05:03 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZpkSM-0000vj-UZ for rsgb_lf_group@blacksheep.org; Fri, 23 Oct 2015 23:05:02 +0100 Received: from mout01.posteo.de ([185.67.36.65]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.86) (envelope-from ) id 1ZpkRI-00028A-Og for rsgb_lf_group@blacksheep.org; Fri, 23 Oct 2015 23:05:01 +0100 Received: from dovecot03.posteo.de (dovecot03.posteo.de [172.16.0.13]) by mout01.posteo.de (Postfix) with ESMTPS id 7372420940 for ; Sat, 24 Oct 2015 00:03:39 +0200 (CEST) Received: from mail.posteo.de (localhost [127.0.0.1]) by dovecot03.posteo.de (Postfix) with ESMTPSA id 3njKMH11NDz5vNB for ; Sat, 24 Oct 2015 00:03:38 +0200 (CEST) Message-ID: <562AAEBA.8080502@posteo.de> Date: Sat, 24 Oct 2015 00:03:38 +0200 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <579355A36AEE9D4FA555C45D556003AB1B25A181@servigilant.vigilant.local> <5628B2D0.7060002@posteo.de> <5629507B.6010907@posteo.de> <360BD4613E1A4110ABB92063DA37C523@pcn5> In-Reply-To: <360BD4613E1A4110ABB92063DA37C523@pcn5> X-Scan-Signature: 75d539362fc79d60c5509fd0caf011e8 Subject: Re: LF: To DK7FC : measuring low levels RF current. Content-Type: multipart/alternative; boundary="------------000101030506070301030303" 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: 4589 This is a multi-part message in MIME format. --------------000101030506070301030303 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hello Andi, Thanks for the info. What does this amperemeter cost? I think i would know how to build an amperemeter for 100 mA FS. However my ranges are 5A / 10A / 20A :-) I'm directly measuring the antenna current, i.e. not on the 50 Ohm level. 73, Stefan Am 23.10.2015 14:53, schrieb F6CNI - Andy - JN19QB: > > Helo Stefan, > > For info, here I am using a *MFJ 834* RF Ammeter. It is working well > on MF band, it just need to be first re-calibrate on MF band (only one > variable resistance to adjust) using a low power signal into a 50 Ohms > pure resistive load. > > It is quite linear for RF current measurement from 25 mA to 3 Amperes, > in 3 swiched scales. > > Using it on the 50 Ohms coaxial cable, just after your TX output, you > have a good estimation of your TX power output from 30 milli watt to > 450 watts. > > You can also use it on the cold end of the antenna side. Depending at > the overall antenna system resistance, you can read the real antenna > current… > > 73 de Andy. > > *From:* DK7FC > *Sent:* Thursday, October 22, 2015 11:09 PM > *To:* rsgb_lf_group@blacksheep.org > *Subject:* LF: M0LMH > Hi MF, > > Since a few hours i'm transmitting WSPR with the variable mains > transformer turned to 0%. So just the driver is switching the FETs. > Anyway a few mW TX power seem to be generated and radiated. I can see > no reading on the RF amperemeter. > Anyway i got 15 spots: > Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az > 2015-10-22 20:14 DK7FC 0.475685 -22 0 JN49ik 1 M0LMH > IO93gx 862 310 > 2015-10-22 20:24 DK7FC 0.475683 -19 0 JN49ik 1 F5WK JN18hp > 452 261 > 2015-10-22 20:44 DK7FC 0.475682 -21 0 JN49ik 1 PA0A JO33de > 449 339 > 2015-10-22 20:14 DK7FC 0.475682 -26 0 JN49ik 1 PA0RDT > JO11tm 428 305 > 2015-10-22 20:14 DK7FC 0.475683 -17 0 JN49ik 1 PA3ABK > JO21it 386 315 > 2015-10-22 20:14 DK7FC 0.475683 -15 0 JN49ik 1 DH5RAE > JN68qv 345 98 > 2015-10-22 20:14 DK7FC 0.475683 -18 0 JN49ik 1 PI4THT > JO32kf 336 338 > 2015-10-22 20:14 DK7FC 0.475683 -15 0 JN49ik 1 DJ0ABR > JN68nt 329 101 > 2015-10-22 20:14 DK7FC 0.475683 -22 0 JN49ik 1 DG8RW > JN69cv 257 77 > 2015-10-22 20:14 DK7FC 0.475682 -23 0 JN49ik 1 DF2JP > JO31hh 256 325 > 2015-10-22 20:54 DK7FC 0.475683 -27 1 JN49ik 1 DC0DX_H > JO31lk 255 332 > 2015-10-22 20:24 DK7FC 0.475684 -24 0 JN49ik 1 DB1EPO > JO31hg 252 325 > 2015-10-22 20:14 DK7FC 0.475684 -21 0 JN49ik 1 DF6NM > JN59nj 175 91 > 2015-10-22 20:14 DK7FC 0.475684 -7 0 JN49ik 1 DK2DB JN48fw > 58 198 > 2015-10-22 20:34 DK7FC 0.475686 -10 0 JN49ik 1 DF8UO > JN48ex 56 206 > > > M0LMH is the best distance. Also in daytime i can see that M0LMH is > receiving me, often beeing the only one from UK. > Does someone know him and his equipment? Would be interesting to know! > In IO93GX, there is not population. Certainly one reason for the good > results... > > 73, Stefan > > PS: Now QRO... --------------000101030506070301030303 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit Hello Andi,

Thanks for the info. What does this amperemeter cost?
I think i would know how to build an amperemeter for 100 mA FS. However my ranges are 5A / 10A / 20A :-) I'm directly measuring the antenna current, i.e. not on the 50 Ohm level.

73, Stefan

Am 23.10.2015 14:53, schrieb F6CNI - Andy - JN19QB:

Helo Stefan,

 

For info, here I am using a MFJ 834 RF Ammeter. It is working well on MF band, it just need to be first re-calibrate on MF band (only one variable resistance to adjust) using a low power signal into a 50 Ohms pure resistive load.

 

It is quite linear for RF current measurement from 25 mA to 3 Amperes, in 3 swiched scales.

 

Using it on the 50 Ohms coaxial cable, just after your TX output, you have a good estimation of your TX power output from 30 milli watt to 450 watts.

 

You can also use it on the cold end of the antenna side. Depending at the overall antenna system resistance, you can read the real antenna current…

 

73 de Andy.

 
From: DK7FC
Sent: Thursday, October 22, 2015 11:09 PM
Subject: LF: M0LMH
 
Hi MF,

Since a few hours i'm transmitting WSPR with the variable mains transformer turned to 0%. So just the driver is switching the FETs. Anyway a few mW TX power seem to be generated and radiated. I can see no reading on the RF amperemeter.
Anyway i got 15 spots:
Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
2015-10-22 20:14 DK7FC 0.475685 -22 0 JN49ik 1 M0LMH IO93gx 862 310
2015-10-22 20:24 DK7FC 0.475683 -19 0 JN49ik 1 F5WK JN18hp 452 261
2015-10-22 20:44 DK7FC 0.475682 -21 0 JN49ik 1 PA0A JO33de 449 339
2015-10-22 20:14 DK7FC 0.475682 -26 0 JN49ik 1 PA0RDT JO11tm 428 305
2015-10-22 20:14 DK7FC 0.475683 -17 0 JN49ik 1 PA3ABK JO21it 386 315
2015-10-22 20:14 DK7FC 0.475683 -15 0 JN49ik 1 DH5RAE JN68qv 345 98
2015-10-22 20:14 DK7FC 0.475683 -18 0 JN49ik 1 PI4THT JO32kf 336 338
2015-10-22 20:14 DK7FC 0.475683 -15 0 JN49ik 1 DJ0ABR JN68nt 329 101
2015-10-22 20:14 DK7FC 0.475683 -22 0 JN49ik 1 DG8RW JN69cv 257 77
2015-10-22 20:14 DK7FC 0.475682 -23 0 JN49ik 1 DF2JP JO31hh 256 325
2015-10-22 20:54 DK7FC 0.475683 -27 1 JN49ik 1 DC0DX_H JO31lk 255 332
2015-10-22 20:24 DK7FC 0.475684 -24 0 JN49ik 1 DB1EPO JO31hg 252 325
2015-10-22 20:14 DK7FC 0.475684 -21 0 JN49ik 1 DF6NM JN59nj 175 91
2015-10-22 20:14 DK7FC 0.475684 -7 0 JN49ik 1 DK2DB JN48fw 58 198
2015-10-22 20:34 DK7FC 0.475686 -10 0 JN49ik 1 DF8UO JN48ex 56 206

M0LMH is the best distance. Also in daytime i can see that M0LMH is receiving me, often beeing the only one from UK.
Does someone know him and his equipment? Would be interesting to know! In IO93GX, there is not population. Certainly one reason for the good results...

73, Stefan

PS: Now QRO...
--------------000101030506070301030303--