Re: LF: RE: Re: TDA2003, TDA2030 for PA?

["Graham" <g8fzk@g8fzk.fsnet.co.uk>]

G..

Just checked ... power -3 db at  140 Khz  .. but the gain/bw  plot shows 20 
db gain at  500 K
but that's running  with 'no' compensation ... so may be a little  'wild' 
hihi
G ..


B Power Bandwidth
(-3 dB)
Gv = 30 dB
Po = 12W RL = 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 
> 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 
> on
> 500kHz.
> I think I got about 6Watts out. Not all the audio ICs have as much 
> 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 ----- 
> From: "Petr Malý" <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 
> 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. 
> Of
> course, mainly 505 kHz is rather out of range so that nothing is 
> 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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