Return-Path: X-Spam-DCC: paranoid 1233; 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=-2.1 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_RCVD_HELO,HTML_50_60,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 t54D9Da0022163 for ; Thu, 4 Jun 2015 15:09:13 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Z0UqO-0006sl-8O for rs_out_1@blacksheep.org; Thu, 04 Jun 2015 14:06:00 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Z0UqN-0006sc-T7 for rsgb_lf_group@blacksheep.org; Thu, 04 Jun 2015 14:05:59 +0100 Received: from rhcavuit02.kulnet.kuleuven.be ([134.58.240.130] helo=cavuit02.kulnet.kuleuven.be) by relay1.thorcom.net with esmtp (Exim 4.85) (envelope-from ) id 1Z0UqL-0008A0-EA for rsgb_lf_group@blacksheep.org; Thu, 04 Jun 2015 14:05:58 +0100 X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-KULeuven-Scanned: Found to be clean X-KULeuven-ID: ED6C412808A.A2592 X-KULeuven-Information: Katholieke Universiteit Leuven Received: from icts-p-smtps-1.cc.kuleuven.be (icts-p-smtps-1e.kulnet.kuleuven.be [134.58.240.33]) by cavuit02.kulnet.kuleuven.be (Postfix) with ESMTP id ED6C412808A for ; Thu, 4 Jun 2015 15:05:51 +0200 (CEST) Received: from ICTS-S-HUB4.luna.kuleuven.be (icts-s-hub4.luna.kuleuven.be [10.112.9.18]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by icts-p-smtps-1.cc.kuleuven.be (Postfix) with ESMTPS id 3BD02403B for ; Thu, 4 Jun 2015 15:05:51 +0200 (CEST) Received: from ICTS-S-MBX1.luna.kuleuven.be ([fe80::edaf:341f:90e:f70e]) by ICTS-S-HUB4.luna.kuleuven.be ([fe80::c11b:83f0:c46c:c366%26]) with mapi id 14.03.0224.002; Thu, 4 Jun 2015 15:05:50 +0200 X-Kuleuven: This mail passed the K.U.Leuven mailcluster From: Rik Strobbe To: "rsgb_lf_group@blacksheep.org" Thread-Topic: LF: IDC-136-BLT 136kHz receivers Thread-Index: AQHQnsE8TZEnAbZGx0a4XFg3NcHrmp2cKVGAgAAlPoWAAAJMSA== Date: Thu, 4 Jun 2015 13:05:50 +0000 Message-ID: <7E7DFBB4D102A04DB5ADC88D66628A4A235626A6@ICTS-S-MBX1.luna.kuleuven.be> References: <1052531792.20150604131722@chriswilson.tv>, In-Reply-To: Accept-Language: nl-BE, en-GB, en-US Content-Language: nl-BE X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mimectl: Produced By Microsoft Exchange V14.3.123.2 x-originating-ip: [10.112.13.11] MIME-Version: 1.0 X-HELO-Warning: Remote host 134.58.240.130 (rhcavuit02.kulnet.kuleuven.be) used invalid HELO/EHLO cavuit02.kulnet.kuleuven.be - verification failed X-Scan-Signature: f9f85a03ab18710b130c40acc03380f0 Subject: RE: LF: IDC-136-BLT 136kHz receivers Content-Type: multipart/alternative; boundary="_000_7E7DFBB4D102A04DB5ADC88D66628A4A235626A6ICTSSMBX1lunaku_" 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: 3433 --_000_7E7DFBB4D102A04DB5ADC88D66628A4A235626A6ICTSSMBX1lunaku_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello Andy, Chris, the circuit diagram can be found in this PDF: http://icas.to/idc-136ii/idc-136ii-kit-manual-eng= .pdf In contradiction to the block diagram at http://icas.to/lineup/idc-136ii-kit-eng.htm the circuit diagram show a J310 wideband preamp be= fore the BPF. I have played with SA612 chip in the past and found that it had rather poor= IMD behaviour compared to a 74HC4053 mixer. 73, Rik ON7YD - OR7T ________________________________ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.org= ] namens Andy Talbot [andy.g4jnt@gmail.com] Verzonden: donderdag 4 juni 2015 14:44 Aan: rsgb_lf_group@blacksheep.org Onderwerp: Re: LF: IDC-136-BLT 136kHz receivers Haven't seen / played / even heard of them, but we can get a rough idea of = its possible performance just by looking at the picture of the PCB on the = web page. Image filterign is teh biggest problem with this single conversi= on route. Assuming all the image filtering is done by those three coils i= n cans that are visible on the photograph:. An AADE design for a suitable third order bandpass filter, with 8kHz bandwi= dth and allowing a compromise 1dB ripple suggests image rejection at 125kH= z will only be around 30dB. (Top coupled capacitor design, so low side r= ejectino is better than high side) Not sure what signals are down there t= o get through, and a highly resonant antenna will help a lot more with imag= e rejection - but if its for a grabber, you're probably going to use a broa= dband active antenna. Can't make out much else from the web page photos, and it give no specifica= tion. But such a simple converter concept can't go hopelessly wrong, if y= ou accept the limited image filter that would be achieved with three tuned = circuits If I were to try that approach, I'd got for an IF of 15 - 19kHz, at the to= p end of normal soundcard coverage, so bringing the image down to 105kHz a= nd making it easier to filter - although there you would just be creeping i= nto LORAN area. Andy G4JNT On 4 June 2015 at 13:17, Chris Wilson > wrote: 04 June 2015 I ordered one of these yesterday as I am getting tired of tying up my TS-590 just listening on LF. I think a few people here may have used these, what are your opinions of them please? http://icas.to/lineup/idc-136ii-kit-eng.htm -- Best regards, Chris mailto:chris@chriswilson.tv --_000_7E7DFBB4D102A04DB5ADC88D66628A4A235626A6ICTSSMBX1lunaku_ Content-Type: text/html; charset="iso-8859-1" Content-ID: <6815BCF1C2726F489230829201148F79@luna.kuleuven.be> Content-Transfer-Encoding: quoted-printable

Hello Andy, Chris,

 

the circuit diagram can be found in this PDF: http://icas.to/idc-136ii/idc= -136ii-kit-manual-eng.pdf

In contradiction to the block diagram at h= ttp://icas.to/lineup/idc-136ii-kit-eng.htm&= nbsp;the circuit diagram show a J310 wideband preamp before the BPF.

I have played with SA612 chip in= the past and found that it had rather poor IMD behaviour co= mpared to a 74HC4053 mixer= .

 

73, Rik  ON7YD - OR7T

 

Van: owner-rsgb_lf_group@blacksheep.org [o= wner-rsgb_lf_group@blacksheep.org] namens Andy Talbot [andy.g4jnt@gmail.com= ]
Verzonden: donderdag 4 juni 2015 14:44
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: IDC-136-BLT 136kHz receivers

Haven't seen / played / even heard of them, but we can get= a rough idea of its possible performance just by looking at the picture of= the PCB on  the web page.  Image filterign is teh biggest proble= m with this single conversion route.   Assuming all the image filtering is done by those three coils in cans that are visi= ble on the photograph:.

An AADE design for a suitable third order bandpass filter, with 8kHz b= andwidth and allowing a compromise 1dB ripple  suggests image rejectio= n at 125kHz will only be around 30dB.   (Top coupled capacitor  d= esign, so low side rejectino is better than high side)   Not sure what signals are down there to get through, and a hi= ghly resonant antenna will help a lot more with image rejection - but if it= s for a grabber, you're probably going to use a broadband active antenna.

Can't make out much else from the web page photos, and it give no spec= ification.  But  such a simple converter concept can't go hopeles= sly wrong, if you accept the limited image filter that would be achieved wi= th three tuned circuits

If I were to try that approach, I'd got for an IF of  15 - 19kHz,= at the top end of  normal soundcard coverage, so bringing the image d= own to 105kHz and making it easier to filter - although there you would jus= t be creeping into LORAN area.

Andy  G4JNT

On 4 June 2015 at 13:17, Chris Wilson <chri= s@chriswilson.tv> wrote:
04 June 2015


I  ordered one of these yesterday as I am getting tired of tying up my=
TS-590 just listening on LF. I think a few people here may have used these,=
what are your opinions of them please?

h= ttp://icas.to/lineup/idc-136ii-kit-eng.htm



--


Best regards,
 Chris                  &= nbsp;         mailto:chris@chriswilson.tv



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