Re: LF: On air again in LF WSPR-15

[Andy Talbot <andy.g4jnt@gmail.com>]

Contragulations,  That is the ONLY other design I have seen for a LF amplifier using directly rectified mains. apart from my own half-bridge version http://g4jnt.com/137tx.pdf     After building that, I always intended doing a full bridge one, but never got round to it - was a bit scared I suspect, and back then FETs were more expensive than they are now.

Andy

www.g4jnt.com

On Wed, 21 Nov 2018 at 14:10, DK7FC <selberdenken@posteo.de> wrote:

Hi Chris,

Yes i published it on Dropbox a few years ago but i think the link
doesn't work any more. I attach the two images here, the size is small
enough.

73, Stefan

Am 21.11.2018 14:40, schrieb Chris Wilson:
>
> Hello DK7FC,
>
> Is  the  H bridge amp a published design Stefan, and if not, would you
> consider posting it please? :)
>
> Wednesday, November 21, 2018, 1:00:23 PM, you wrote:
>
>   
>>
>>   Hi Luis,
>>
>>   thanks for the nice readably summary report.
>>   Oh yes it was an impressing night and good resultsfor us. I saw
>> you were decoded at SM2DJK which is a good distance, and R7NT was
>> seen at 2E0ILY. There are more challenges like the path from EB8ARZ
>> to SM2DJK, that would be about 4000 km and still inside the continent.
>>   I also thought about LU8YD but also about PY2PLL.
>>   EB8ARZ has the perfect RX location, so if LU8YD would transmit on
>> LF, like in the past, it could work in WSPR-15 just before the sunrise in EA8.
>>
>>   About the MOSFET discussion, i'm using IRFP460A types in H bridge
>> configurations from SLF to MF, i.e. the full spectrum :-) Bridge
>> voltage is 320 V DC, the rectified mains voltage.
>>   With the currently pair (4 pcs) of FETs i'm TXing since hundreds
>> of hours on LF without problems. They are of course in TO-247 design
>> and cost just 2.2 EUR, so a BANG/year wouldn't really hurt.
>>
>>   73, Stefan
>>     
>
>