Message-ID: <CF7575B0113640F98BB92869625A5DE2@AGB>
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <BE4A5829B4DB4F54ACE6C6FD0AA72DCF@gmc.net> <86B4F549F8F247DDA470143B3BE77364@Hugh> <008c01c9ad63$4e9a9190$6401a8c0@asus>
In-Reply-To: <008c01c9ad63$4e9a9190$6401a8c0@asus>
Date: Wed, 25 Mar 2009 19:28:27 -0000
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Subject: Re: LF: RE: Re: TDA2003, TDA2030 for PA?
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G..

Just checked ... power -3 db at  140 Khz  .. but the gain/bw  plot shows 20=20
db gain at  500 K
but that's running  with 'no' compensation ... so may be a little  'wild'=20
hihi

G ..


B Power Bandwidth
(-3 dB)
Gv =3D 30 dB
Po =3D 12W RL =3D 4W 10 to 140,000 Hz



--------------------------------------------------
From: "Gary - G4WGT" <g4wgt@tiscali.co.uk>
Sent: Wednesday, March 25, 2009 4:03 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: LF: RE: Re: TDA2003, TDA2030 for PA?

>
> Hi Petr,
>
> I have tested a TDA2030 for a 500KHz driver & is OK for 136KHz as other
> authors have stated.
>
> It does fall off very rapidly from 200KHz & higher & is of no use at=20
> 500KHz.
>
> 73
>
> Gary - G4WGT.
>
>
>
> -----Original Message-----
> From: owner-rsgb_lf_group@blacksheep.org
> [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Hugh_m0wye
> Sent: 25 March 2009 15:01
> To: rsgb_lf_group@blacksheep.org
> Subject: LF: Re: TDA2003, TDA2030 for PA?
>
> I successfully made a TDA2030 amplifier which i used for all my intial
> experimenting on 137kHz
> Photo http://www.m0wye.radiouk.com/lfamp.jpg
> The data sheet for this IC claims a bandwidth of 140kHz so it won't work=20
> on
> 500kHz.
> I think I got about 6Watts out. Not all the audio ICs have as much=20
> bandwidth
>
> as this.
> You need a matching circuit on the output to convert the low impedance of
> the amp to 50 ohms - or whatever your antenna system uses.
> 73
> Hugh M0WYE
>
>
>
>
> ----- Original Message -----=20
> From: "Petr Mal=FD" <p.maly@gmc.net>
> To: <rsgb_lf_group@blacksheep.org>
> Sent: Wednesday, March 25, 2009 1:38 PM
> Subject: LF: TDA2003, TDA2030 for PA?
>
>
> Hi all,
>
> My intention is to build a small transmitter up to some 10W for 136 and=20
> 505
> kHz, this time not the D class, but B or AB class.
> I think of employing AF amplifiers such as TDA2003, TDA2030, or similar.=20
> Of
> course, mainly 505 kHz is rather out of range so that nothing is=20
> guaranteed.
>
> This is why I ask before experimenting.
> Did anybody try to use these for 136/505 kHz?
>
> Tks, 73, Petr, OK!FIG
> http://ok1fig.nagano.cz
>
>
>
>
>



>
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