Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w3AAbR41025749 for ; Tue, 10 Apr 2018 12:37:30 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1f5qVL-0000L8-VJ for rs_out_1@blacksheep.org; Tue, 10 Apr 2018 11:27:59 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1f5qVD-0000Kx-S7 for rsgb_lf_group@blacksheep.org; Tue, 10 Apr 2018 11:27:51 +0100 Received: from resqmta-ch2-07v.sys.comcast.net ([69.252.207.39]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1f5qVA-000227-7l for rsgb_lf_group@blacksheep.org; Tue, 10 Apr 2018 11:27:50 +0100 Received: from resomta-ch2-15v.sys.comcast.net ([69.252.207.111]) by resqmta-ch2-07v.sys.comcast.net with ESMTP id 5qSqfzzy3o60r5qT9f4lVk; Tue, 10 Apr 2018 10:25:43 +0000 X-DKIM-Result: Domain=comcast.net Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20161114; t=1523355943; bh=0DKibAbfuseSXPWF8UAGZEwMEQGgHM+cnQCmZzSd5ig=; h=Received:Received:From:Subject:To:Content-Type:MIME-Version:Date: Message-ID; b=bsuK0LZIbtvZ2JG34d+zt49KqIA0OwGMIUCPfMwi0fC9M0Vss6WEReV7Mv+alrSH4 6Xf8Ax0APzv6fbBAPjKb2mIk/Wf2IlBNUEdsxgZAIDZ4/Fe0GbkimnCMkDzSwmusqm pwO7ncmpad2MrEzYnc0dy+L2I7AXmL38yM7RCv2+R3pUIV0qHpntjiLzVz8AAg0ZAP P4OY2HLz33el0Oo/0j18MA6/sEQBy6hbnL8YBRryayPTHU7asOISSA5kvssSpmrYBA ncW4yKDL6PjhkHhDTgtqtHS7xPMQKngzOTnVi4vqOUIoV4+898xDff9C3ncPisO3RD 5WCoQeLfezKyg== Received: from Optiplex980-PC ([73.4.253.141]) by resomta-ch2-15v.sys.comcast.net with SMTP id 5qT6fiYqnswa25qT8f5Izz; Tue, 10 Apr 2018 10:25:43 +0000 From: "jrusgrove@comcast.net" To: "rsgb_lf_group@blacksheep.org" MIME-Version: 1.0 References: <162a4797468-1db9-bdf2@webjas-vae168.srv.aolmail.net> <197556217.20180409124931@gmail.com> <37574432-b72e-f2d1-0e85-af19dd970817@n1bug.com> <4D19B3707137430CBE04857FBA5C80B1@gnat> <1b882ae9-fede-3ec4-256e-9b068d3acf99@n1bug.com> <1539CCA16B9A4092972CB000BE4C440A@DELL4> <7606DCC26D954BD1AE881D54F9F2894A@DELL4> <6832cf3c-a6e3-7b11-79dd-95f42cd9bcee@n1bug.com> Date: Tue, 10 Apr 2018 06:25:39 -0400 Message-ID: <1UQRR1pNEA.1SfJSy9fbpz@optiplex980-pc> In-Reply-To: <6832cf3c-a6e3-7b11-79dd-95f42cd9bcee@n1bug.com> User-Agent: OEClassic/2.7 (Win7; P; 2017-02-12) X-Mailer: OEClassic/2.7 (Win7; P; 2017-02-12) X-CMAE-Envelope: MS4wfLRC/tgFN/FJLIsyPnJEcCgcpKTUTJpckosHqMDePQw7vnivjZZPqehvR0SWapoxiwaDfEZ/HHI52V1chBXMtCoKJ/MyxkcBBWhZMO2N+/owRH8FWJsW z1/DEz74NhzlAC2HmQCsxlo2prRNINRcIA9msF/QpTcrFYAnxWy8CQ18EpZXtES4B7gAaffEM+FJCw== X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Paul Okay on 78 material. Wonder if you measured your snubber caps? Notice they're maroon color which would indicate they're old ... possibly used or an off brand? All new CDE mica caps have been yellow in color for some time. Can't tell from the pix ... are they really DM19 size? The russian blue glass mica's that Chris mentioned (same as I used) are excellent. I've used these in applications where other 'lesser' mica's were pushed beyond their limits. Will check to see if I have a couple extra. Don't be in a hurry to start changing values since a number of these amps have been built 'to spec' with the no ringing problem. There's something in your amplifier / system thats causing the anomoly. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (jrusgrove[at]comcast.net) 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: bc223f74149f392a7d9f3881f05f1e70 Subject: Re: LF: W1VD amp help - more waveforms Content-Type: multipart/alternative; boundary="1a=_i4ITZ5tpayalaJUEuFj0cJX2qjboED" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=HTML_MESSAGE, TO_ADDRESS_EQ_REAL autolearn=no version=2.63 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 This is a multi-part message in MIME format --1a=_i4ITZ5tpayalaJUEuFj0cJX2qjboED Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Paul Okay on 78 material. Wonder if you measured your snubber caps? Notice=20 they're maroon color which would indicate they're old ... possibly use= d or an=20 off brand? All new CDE mica caps have been yellow in color for some ti= me. =20 Can't tell from the pix ... are they really DM19 size? The russian bl= ue glass mica's=20 that Chris mentioned (same as I used) are excellent.=20 I've used these in applications where other 'lesser' mica's were pushe= d beyond=20 their limits. Will check to see if I have a couple extra.=20 Don't be in a hurry to start changing values since a number of these a= mps have been built 'to=20 spec' with the no ringing problem. There's something in your amplifier= / system=20 thats causing the anomoly. Did you try using a wider connection to ground on the snubber resistor= ? Grab=20 some zip cord off a little used lamp ... it will be fine for 'low powe= r'=20 testing. It will wind tight aagainst the core. Jay W1VD =20 ----- Original Message ----- From: N1BUG Reply-To: To: Sent: 4/9/2018 9:37:37 PM Subject: Re: LF: W1VD amp help - more waveforms The core is 78 material. I tried again with different wire. The winding is somewhat tighter on the core but definitely not what I was hoping for. Clearly I am not bringing required skills to the table on constructing this. Drain waveforms became somewhat asymmetrical with one phase having a somewhat different shape from the other but peak voltage was similar... 65V on one side, 63V on the other with 13VDC supply. I'm sure this was a bad idea but out of curiosity I tried adding another 500 pf in parallel with the 1500 pf snubber cap on one side only. Power output and efficiency did not change but peak voltage on that side dropped a couple of volts. I then increased that side to a total of 3000 pf. Power output and efficiency has still not changed at all but peak voltage on that side is down to 50V and it stops ringing significantly sooner than the other side. Does this suggest anything other than insanity of the builder? Paul On 04/09/2018 05:29 PM, jrusgrove@comcast.net wrote: > Paul >=20 > Maybe try some 14 or 16 gauge lamp cord ... it's=20 pretty pliable and can be wound tight against the=20 > core.=20 That's what I used in the 500 watt deck. Put a piece of wet paper towe= l around the insulation=20 > when soldering to prevent 'melt=20 back'. >=20 > Is your core 77 or 78 material? >=20 > On your driver board ... are there reasonably wide traces ... especi= ally from the 12 volt power=20 > supply to the IR2110? Peak currents can be high driving the gate C. = Is the 12 volt supply reasonably=20 > stout? >=20 > Jay W1VD --1a=_i4ITZ5tpayalaJUEuFj0cJX2qjboED Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline
Paul
 
Okay on 78 material.
 
Wonder if you measured your snubber caps? Notice they're mar= oon color which would indicate they're old ... possibly used or an off= brand? All new CDE mica caps have been yellow in color for some = time.  Can't tell from the pix ... are they really DM19 size?&nbs= p; The russian blue glass mica's that Chris mentioned (same as I = used) are excellent. I've used these in applications where other 'less= er' mica's were pushed beyond their limits. Will check to see if = I have a couple extra. Don't be in a hurry to start changing= values since a number of these amps have been built 'to spec' with th= e no ringing problem. There's something in your amplifier / system tha= ts causing the anomoly.
 
Did you try using a wider connection to ground on the snubbe= r resistor? Grab some zip cord off a little used lamp ... it will be f= ine for 'low power' testing. It will wind tight aagainst the core.
 
Jay W1VD
 
      
 
 
----- Original Message -----
From: N1BUG <paul@n1b= ug.com>
Sent: 4/9/2018 9:37:37 PM
Subject: Re: LF: W1VD amp help - more waveforms
The core is 78 material.

I tried again with different wire. The= winding is somewhat tighter
on the core but definitely not what I = was hoping for. Clearly I am
not bringing required skills to the ta= ble on constructing this.

Drain waveforms became somewhat asymm= etrical with one phase having a
somewhat different shape from the o= ther but peak voltage was
similar... 65V on one side, 63V on the ot= her with 13VDC supply.

I'm sure this was a bad idea but out of = curiosity I tried adding
another 500 pf in parallel with the 1500 p= f snubber cap on one side
only. Power output and efficiency did not= change but peak voltage on
that side dropped a couple of volts. I = then increased that side to a
total of 3000 pf. Power output and ef= ficiency has still not changed
at all but peak voltage on that side= is down to 50V and it stops
ringing significantly sooner than the = other side. Does this suggest
anything other than insanity of the b= uilder?

Paul



On 04/09/2018 05:29 PM, jrusgrove@comcast.net wrote:
>= Paul
>
> Maybe try some 14 or 16 gauge lamp cord ... it'= s pretty pliable and can be wound tight against the
> core. Tha= t's what I used in the 500 watt deck. Put a piece of wet paper towel a= round the insulation
> when soldering to prevent 'melt back'.>
> Is your core 77 or 78 material?
>
> On yo= ur driver board ... are there reasonably wide traces ... especially fr= om the 12 volt power
> supply to the IR2110? Peak currents can = be high driving the gate C. Is the 12 volt supply reasonably
> = stout?
>
> Jay W1VD
--1a=_i4ITZ5tpayalaJUEuFj0cJX2qjboED--