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References: <5772DAC0.7080001@df3lp.de>
From: Andy Talbot <andy.g4jnt@gmail.com>
Date: Tue, 28 Jun 2016 22:15:55 +0100
Message-ID: <CAA8k23TGuNuOZcnJA42=EDxZgHMAVNeq9SM7=UhvTz6Noqa_FA@mail.gmail.com>
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: OT: Racal vra549c Tuner
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It is not that specific model, but I do have a small man-pack type Racal
auto ATU that has a not totally dissimilar output stage

2C10 is 68pF
2C13 is 180pF

But in mine 2C11 does not exist.

The main inductors and capacitors use the same configuration, except that a
bank of inductors has a separate bypass to reduce stray L at high
frequencies.

The circuit diagram can be found at http://www.g4jnt.com/DropF/racalatu.gif
I don't know its type number, I only had the PCB and it is now mounted in a
diecast box I don't want to dismantle

Andy  G4JNT


On 28 June 2016 at 21:14, Peter <pws@df3lp.de> wrote:

> Hi All,
>
> Off topic:
> I need some info about the Racal vra549c antenna tuner.
> All I have is the schematic:
> http://lf-radio.de/misc/sw/Racal_vra549c_schem.png
>
> I'm looking for the values of those 3 capacitors at the
> antenna shown on the right: 2C10, 2C11, 2c13. I know
> that they are intended to rotate/shift the antenna
> impedance into a region where the subsequent circuit
> can handle it (guess above ~10 MHz).
>
> ???
>
> 73 de df3lp,
> Peter
>
>

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<div dir=3D"ltr">It is not that specific model, but I do have a small man-p=
ack type Racal auto ATU that has a not totally dissimilar output stage<div>=
<br></div><div>2C10 is 68pF</div><div>2C13 is 180pF</div><div><br></div><di=
v>But in mine 2C11 does not exist.</div><div><br></div><div>The main induct=
ors and capacitors use the same configuration, except that a bank of induct=
ors has a separate bypass to reduce stray L at high frequencies.</div><div>=
<br></div><div>The circuit diagram can be found at=C2=A0<a href=3D"http://w=
ww.g4jnt.com/DropF/racalatu.gif">http://www.g4jnt.com/DropF/racalatu.gif</a=
></div><div>I don&#39;t know its type number, I only had the PCB and it is =
now mounted in a diecast box I don&#39;t want to dismantle</div><div><br></=
div><div>Andy =C2=A0G4JNT</div><div><br></div></div><div class=3D"gmail_ext=
ra"><br><div class=3D"gmail_quote">On 28 June 2016 at 21:14, Peter <span di=
r=3D"ltr">&lt;<a href=3D"mailto:pws@df3lp.de" target=3D"_blank">pws@df3lp.d=
e</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margi=
n:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi All,<br>
<br>
Off topic:<br>
I need some info about the Racal vra549c antenna tuner.<br>
All I have is the schematic:<br>
<a href=3D"http://lf-radio.de/misc/sw/Racal_vra549c_schem.png" rel=3D"noref=
errer" target=3D"_blank">http://lf-radio.de/misc/sw/Racal_vra549c_schem.png=
</a><br>
<br>
I&#39;m looking for the values of those 3 capacitors at the<br>
antenna shown on the right: 2C10, 2C11, 2c13. I know<br>
that they are intended to rotate/shift the antenna<br>
impedance into a region where the subsequent circuit<br>
can handle it (guess above ~10 MHz).<br>
<br>
???<br>
<br>
73 de df3lp,<br>
Peter<br>
<br>
</blockquote></div><br></div>

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