Return-Path: Received: (qmail 59735 invoked from network); 22 Jan 2004 23:06:22 -0000 Received: from unknown (HELO ptb-mxscan02.plus.net) (212.159.14.236) by ptb-mailstore02.plus.net with SMTP; 22 Jan 2004 23:06:22 -0000 Received: (qmail 54216 invoked from network); 22 Jan 2004 23:06:21 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore02.plus.net (212.159.14.216) by ptb-mxscan02.plus.net with SMTP; 22 Jan 2004 23:06:20 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (Exim) id 1Ajnu0-000Dt2-2X for dave@picks.force9.co.uk; Thu, 22 Jan 2004 23:06:20 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Ajnti-0003Mw-2L for rs_out@blacksheep.org; Thu, 22 Jan 2004 23:06:02 +0000 Received: from [62.58.50.88] (helo=postbode01.zonnet.nl) by post.thorcom.com with esmtp (Exim 4.14) id 1Ajntg-0003Mn-PT for rsgb_lf_group@blacksheep.org; Thu, 22 Jan 2004 23:06:00 +0000 Received: (qmail 20306 invoked by uid 10); 22 Jan 2004 23:05:30 -0000 Received: (vexira-qq 20266-9983D0CC invoked from network) 23 Jan 2004 00:05:28 +0100 X-Fake-Domain: unknown Received: from unknown (HELO ibm) ([62.59.190.37]) (envelope-sender ) by postbode01.zonnet.nl (qmail-ldap-1.03) with SMTP for < >; 22 Jan 2004 23:05:28 -0000 X-Bad-Message-ID: no DNS (ibm) Message-ID: <001401c3e13b$36201c60$2102000a@ibm> From: "Dick" To: rsgb_lf_group@blacksheep.org References: <000c01c3e02e$600a21a0$01eafc3e@l8p8y6> <001501c3e058$ba617980$2102000a@ibm> <002501c3e121$12a54fe0$2102000a@ibm> Date: Thu, 22 Jan 2004 23:57:18 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Antivirus: checked by Vexira MailArmor (version: 2.0.1.16; VAE: 6.23.0.2; VDF: 6.23.0.29; host: postbode01.zonnet.nl) Subject: LF: more on my 'nasty'136kHz project............. Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.3 required=5.0 tests=FROM_ENDS_IN_NUMS,HTML_20_30,HTML_MESSAGE autolearn=no version=2.60 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SPAMFiltered: yes X-Spam-Rating: 2 Content-transfer-encoding: 8bit

Hello all,

yeah, well, once being amateur, means mostly always an ham, hihi.

and that means...............exact........I just can't give up.............

so, had an closer look at the 'remains' sofar..........

I haven't checked the waveform as Angelo suggested, but it might well be a

possible trouble source involved.

Maybe with help of the 136-community around here I might be able to solve

the problems and become QRV with a decent signal.

Well, here is what I've done sofar:

I am using an 4049 as an oscillator, with some of it's ports used as buffer.

I'm using a little lowpass filter behind the VFO, and the ouput is somewhere

around -5 to 0 dBm.

I rebuild (yes, I did.........) the divided circuit, first another lowpass filter so, now

having a fairly 'clear' 2192kHz available. (second harmonic more then 60dB down)

This around -5dBm signal goes into pin 11 of an 74HCT4060.

(I put an 10M resistor between pin 10 and 11)

Pin 12 and 8 are grounded; Vcc on pin 16.

It draws 30mA (!) at 12V so, I now put a 150 Ohm resistor between pin16 and the 12V supply,

in order to limit the current.

Of course I put the usual capacitor to ground at pin 16. (330nF)

I get +17dBm out on 137kHz now.

There are a lot of harmonics in the (unfiltered) output; especially the 3f, 5f, 7f etc.

So, at least I am producing a signal on 137kHz (and maaaaaaaaaaaany other freqs) now.

At this point I am not sure what to do.....filtering or not??

I suppose I get these harmonics again in later (driver) stages so, maybe better to

do it at the end..........

How to key is the next question.

I want to leave the VFO on all the time for better stability.

The 4060 will be switched off in RX situation, to aviod having a signal on 137kHz,

and in my receiver blocking the RX..........

I did some tests with the keying circuit used by OM2TW and DF3LP/DJ1ZB in their designs

using 2 stages with BC549, from which the first one is switched in its emitter.

However, this did not work fine.

I was able to key, but the output level was much lower then it's input, and the level of

harmonics etc where worse, compaired to the input signal of the circuit.

I do have some TDA2030's and my plan is to use the OM2TW design in order to get

5Watt or so, driving the rest...........

I do have some core's that might be usuable.I ordered defect computer SMPS powersupply's

in order to get some junk-components.............

One of the core's is likely an T106-26, and I do have a pair of T50-18's as well.

Wonder if the last ones can be used for the step-up transformer in OM2TW's design......

Well, now having some sleep....looking foreward to see some comments tips...

By the way, I still have 2 stacked beverages of 400m length, pointing towards USA up........

Maybe find some time next weekend to listen on 137kHz with it.....

73 Dick, pa4vhf (desperate trying to get on 137kHz, hihi)