Message-ID: <506A399A.2070800@iup.uni-heidelberg.de>
Date: Tue, 02 Oct 2012 02:47:22 +0200
From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= <Stefan.Schaefer@iup.uni-heidelberg.de>
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: <BLU153-W24D0C2EF3574121D01B5B6CF860@phx.gbl>
In-Reply-To: <BLU153-W24D0C2EF3574121D01B5B6CF860@phx.gbl>
Subject: Re: LF: LF/MF modification of TS850 for LF
Content-Type: multipart/alternative;
 boundary="------------030605010004010007050605"
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


This is a multi-part message in MIME format.
--------------030605010004010007050605
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Hi Laurence,

Have you tried to check the increase of the signal voltage at higher 
frequencies to see what e.g. doubling of that C causes? Is there no 
increase at all?
Do you have the schematic of that section?

73, Stefan/DK7FC

Am 02.10.2012 02:31, schrieb Laurence KL7UK:
>
> Looking for a bit of assistance.
>
>  Ive modded my TS850 to allow LF/MF transmit from info from 
> http://we0h.us/Amateur_Radio_stuff/TS850/ts_850_lf_tx_mod.pdf  (thanks 
> Mike, original by Bob ZL2CA)  but the 
> "supplemental" parallel capacitor value in uF to increase the LF level 
> isnt mentioned.
>
> Ive actually tried another 0.01 and smaller and higher values but at 
> 137kHz it doesnt appear to increase the level - any takers or 
> experiences out there who have modded the beast?
>
> We had a load of snow here at the weekend but thankfully its gone 
> already and Im in the garden pulling up new ropes into 2 Spruce trees 
> - a bit stronger than the bendy Birch and Ill attempt to pull up the 
> loop this week. The loop will be slightly bigger, about 50m in length 
> and slightly higher than WD2XDW in Bartlesville. We will see. 
> COnditions are lousy at LF and MF given the Geo/Mag at this latitude 
> but I was hearing Eu on 20m over the Pole pre dawn. We lose nearly 6 
> mins of sun per day at this time of year....
>
> Laurence KL1X
>
>
>
> "The TS-850 transmit drive to the transverter port is reasonably 
> broadband as manufactured, and passes
>
>
> some LF energy for amplification using an external LF amplifier. It is 
> difficult to modify the TS-850
>
>
> circuitry to decrease the LF droop without impacting on response at 
> other HF bands. One modification
>
>
> to improve low frequency response is to supplement the value of C219 
> (a 0.01 uF capacitor, located
>
>
> near L88). It is possible to solder a parallel capacitor to the top 
> side of the RF Unit PCB. Otherwise
>
>
> the "broadband" circuits in the TS-850 transmit drive are accepted for 
> what they are. With C219
>
>
> supplemented in value, 180 kHz output from IF OUT 1 is between about 
> 100 and 250 millivolts,
>
>
> whereas on HF it is more like 1 volt."

--------------030605010004010007050605
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <meta content="text/html; charset=ISO-8859-1"
 http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Hi Laurence, <br>
<br>
Have you tried to check the increase of the signal voltage at higher
frequencies to see what e.g. doubling of that C causes? Is there no
increase at all? <br>
Do you have the schematic of that section?<br>
<br>
73, Stefan/DK7FC<br>
<br>
Am 02.10.2012 02:31, schrieb Laurence KL7UK:
<blockquote cite="mid:BLU153-W24D0C2EF3574121D01B5B6CF860@phx.gbl"
 type="cite">
  <style><!--
.hmmessage P
{
margin:0px;
padding:0px
}
body.hmmessage
{
font-size: 10pt;
font-family:Tahoma
}
--></style>
  <div dir="ltr"><br>
Looking for a bit of assistance.<br>
&nbsp;<br>
&nbsp;Ive modded my TS850 to allow LF/MF transmit from info from&nbsp; <a
 moz-do-not-send="true"
 href="http://we0h.us/Amateur_Radio_stuff/TS850/ts_850_lf_tx_mod.pdf">http://we0h.us/Amateur_Radio_stuff/TS850/ts_850_lf_tx_mod.pdf</a>&nbsp;
(thanks Mike, original by Bob&nbsp;ZL2CA) &nbsp;but the
"supplemental"&nbsp;parallel&nbsp;capacitor value in uF to increase the LF level
isnt mentioned. <br>
&nbsp;<br>
Ive actually tried another 0.01 and smaller and higher values but at
137kHz it doesnt appear to increase the level - any takers or
experiences out there who have modded the beast? <br>
&nbsp;<br>
We had a load of snow here at the weekend but thankfully its gone
already and Im in the garden pulling up new ropes into 2 Spruce trees -
a bit stronger than the bendy Birch and Ill attempt to pull up the loop
this week. The loop will be slightly bigger, about 50m in length and
slightly higher than WD2XDW in Bartlesville. We will see. COnditions
are lousy at LF and MF given the Geo/Mag at this latitude but I was
hearing Eu on 20m over the Pole pre dawn. We lose nearly 6 mins of sun
per day at this time of year....<br>
&nbsp;<br>
Laurence KL1X<br>
&nbsp;<br>
&nbsp;<br>
  <font face="TimesNewRomanPSMT">&nbsp;<br>
  <p align="LEFT">"The TS-850 transmit drive to the transverter port is
reasonably broadband as manufactured, and passes</p>
  <br>
  <p align="LEFT">some LF energy for amplification using an external LF
amplifier. It is difficult to modify the TS-850</p>
  <br>
  <p align="LEFT">circuitry to decrease the LF droop without impacting
on response at other HF bands. One modification</p>
  <br>
  <p align="LEFT">to improve low frequency response is to supplement
the value of C219 (a 0.01 uF capacitor, located</p>
  <br>
  <p align="LEFT">near L88). It is possible to solder a parallel
capacitor to the top side of the RF Unit PCB. Otherwise</p>
  <br>
  <p align="LEFT">the "broadband" circuits in the TS-850 transmit drive
are accepted for what they are. With C219</p>
  <br>
  <p align="LEFT">supplemented in value, 180 kHz output from IF OUT 1
is between about 100 and 250 millivolts,</p>
  <br>
whereas on HF it is more like 1 volt."<br>
  </font> </div>
</blockquote>
</body>
</html>

--------------030605010004010007050605--