Message-ID: <15c31777bdd.marcocadeddu@tin.it>
Date: Mon, 22 May 2017 20:42:13 +0200 (CEST)
From: "marcocadeddu@tin.it" <marcocadeddu@tin.it>
To:  <rsgb_lf_group@blacksheep.org>
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Subject: R: Re: R: Re: R: Re: LF: RE: Combining LF amps revisited
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Hello Chris, Hello Clemens,

thanks for the confirmation, softwares are wonderful but is always 
better have a rough idea of the possible resoult and check it ;-) 
anyway if he will have an update it is a nice tool (for the calculation 
a simple pocket calculator is enough, but you save a lot of time if you 
have not to search on the datasheets the toroids parameters).

Chris will be happy to share with you and the other LF friends my 
search for the best cooking recipe :-D
I'm doing nothing new: simply merging the Andy's switching PA with an 
old homemade HF PA made according the DL9AH project. The power supply 
in this case is not direct rectification of the mains but a switched 
charging of 2 elcap banks giving 180 Vdc with available power in the 
range of 1200W.
The new LF PA use this PS and the chassis, now most part of the work is 
done (PS and PA) I still have to prepare the driver, antenna switching 
and the PA will be ready for cooking ;-)
I plan to test with low tension 12V, then 30, then 50 watching how it 
works if everything goes smooth will apply the 180V and then I could 
convert the switching PS in direct rectification (the cap banks are 
made with 30 680uF 200V electrolitics so it needs simply to rearrange 
the banks and add the fullwave rectifier).

If the PA runs fine probably will try to cook the antenna !

Will keep you posted after the weekend

73 Marco IK1HSS
----Messaggio originale----
Da: dead.fets@gmail.com
Data: 22-mag-2017 11.33
A: <rsgb_lf_group@blacksheep.org>
Ogg: Re: R: Re: R: Re: LF: RE: Combining LF amps revisited

22nd May 2017

Hello Marco,

I would be very interested to read / see your endeavours with this new
amp,  if you have the time and inclination to document what you are up
to? Interest seems to have shifted slightly to the wonderful Ebnaut on
VLF  at  the  moment, something i one day wish to try, but not until I
perfect my LF set up a lot more! Good lick with the new design!

Tuesday, May 16, 2017, 6:40:31 PM, you wrote:


> Hello Chris,

> happy to read that increasing the turn number you can make the life 
> easier to the toroids ;-) (the FETs also enjoy hi).
> I'm not a professional, but using the formula and taking 
> care of respect of the Bmax of 0.1T, I had (up o now) no problems 
with
> xformers. Since some years I switched to  Epikote forms wich are 
> looking better for low frequencies (and here in Italy are also 
cheaper
> of Amidon cores).
> In the weekend I should start some trials with simil Decca approach: 
> the PS at 180Vdc is already running and could be later transformed 
in 
> direct rectification of the main aiming to 1kW which should then 
allow
> to reach the 1W. Still running 250 or 20W on LF with satisfactory 
> resoult considering the city antenna and the season :-)

> 73, Marco IK1HSS


-- 
Best regards,
 Chris                            mailto:dead_fets@gmail.com