TDA2003 used for Heyphone on 87kHz.
73
John
*********** REPLY SEPARATOR ***********
On 25/03/2009 at 16:03 Gary - G4WGT wrote:
>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: [email protected]
>[mailto:[email protected]] On Behalf Of Hugh_m0wye
>Sent: 25 March 2009 15:01
>To: [email protected]
>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" <[email protected]>
>To: <[email protected]>
>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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