Re: LF: TDA7498 2x100W audio PA for LF use ??

[LineOne <dhchurch@lineone.net>]

It comes from HongKong via Ebay usually as a kit but also ready-built for only a little extra cost. If you look for a business called "HiFiSpot" it gives you a number of interesting thingsnow including a 500W amplifier with a -3dB point at 500kHz. I think this won't apply to continuous sine wave but I've just bought one and now have to build the huge  power supply.
The 300W amplifier I run from a 30+30V 5A supply with a toroidal transformer, unregulated.

Good hunting, Hugh, M0DSZ

Hi Hugh

 

Were did you got the kit ? Is it still available ?

 

73 de Luis

EA5DOM

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De: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de LineOne
Enviado el: martes, 08 de diciembre de 2015 12:07
Para: rsgb_lf_group@blacksheep.org
Asunto: Re: LF: TDA7498 2x100W audio PA for LF use ??

I bought a 300W amplifier kit, all the small transistors have an "ft" in the VHF region and the power transistors ft is 15MHz. Small modifications include changing the Zobel network and bypassing some electrolytics with 100nF. Latterly I have fitted 250V power transistors to replace the 150V, some spikes were liable to "kill" the originals.
It gives me 300W dc input, about half available as RF power. Forced cooling is necessary.

On 08/12/2015 09:41, VIGILANT Luis Fernández wrote:

Hi LF

I have read about using old TDA2010 audio modules as exciter stages for LF amplifiers

Searching the web have found that there is actually a bunch of cheap audio amplifiers based

in TDA7498 which is 2x100W. I wonder if this worths to get some watts into LF. Mat be the

two outputs can be also combined if feeded ati phase ?

Have a look at one of this here

http://www.ebay.com/itm/New-TDA7498-100W-100W-Class-D-Amplifier-Board-Computer-Amplifier-/310956174740?hash=item48666ead94:g:WXcAAOxyYANTcIW4

73 de Luis

EA5DOM