LF: RE: TDA2030 amplifier by OM2TW

["Gasparik Richard" <Richard.Gasparik@siemens.com>]

Hi Dick,

 

L3/L4 is a step up transformer. Normaly the TDA 2030 have 4-8 Ohm output impedance. You must look for an toroid with very high permeability (2000 and more) and make an L3:L4 = 1:3 transformer (in my case 11 turns primary:33turns secondary) whitch is 1:9 impedance transformer.

 

73 de Rich OM2TW

 

 -----Original Message-----
From: Dick [mailto:knaap159@zonnet.nl]
Sent: Wednesday, January 21, 2004 8:35 PM
To: rsgb_lf_group@blacksheep.org
Subject: LF: TDA2030 amplifier by OM2TW

Hello all,

 

As I haven't OM2TW's emailadress right now, I'll ask here.

I found an pdf.drawing of the TDA2030 amplifier giving 5Watts or so on 136kHz.

however, at hte output stage there are two coils L3/L4 (ouput transformer) with no

further details mentioned.

Can anyone help me with detailed info about the value/or how to construct these coils?

Also some uncertainty about C21 and C22, are they elco's or normal C's????

 

73 Dick, pa4vhf

 

(now probably first try to create QRP in an easy way.......)