Message-ID: <59317470.9000303@posteo.de>
Date: Fri, 02 Jun 2017 16:21:36 +0200
From: DK7FC <selberdenken@posteo.de>
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To: rsgb_lf_group@blacksheep.org
References: <15c691384e7.marcocadeddu@tin.it>
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Subject: Re: R: Re: R: Re: R: Re: R: Re: R: Re: R: Re: R: Re: R: LF: Re: I:
 Fw: For today the FETs survived...
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Hi Marco, Chris,

Greetings from the lower end of the spectrum. It is quite silent down 
here, no contests, no band plans, not even complaints about key 
clicks!!!! (so relaxing), no pile ups, just the nature is speaking to me 
from time to time. And ZEVS is whispering but i can't hear it so far.
I'm envious, up on the microwaves with just a few km of wavelength you 
have so much bandwidth, you can tune down by 1 kHz and more, whereas i 
would crash into the DC wall when attempting to try that. Also your 
coils are so small, the antenna current so high, the voltages so low, 
the ERP so high, and there are so many people daily.
However my phase is so stable down here and so reproducable :-) So i can 
can talk very slowly or say just one word per day. And i'm diving below 
the switch mode power supply QRM and inbetween the mains hum :-)
It all has its pros and cons. Anyway we have a nice hobby on the real 
low frequencies.
I'll visit you again in the near future on 137 kHz. Maybe we can try 
something like JT9 or QRSS?

73, Stefan


Am 02.06.2017 15:51, schrieb marcocadeddu@tin.it:
> Hello Chris,
>
> yes I'm testing into a dummy load and getting troubles trepassing the
> 15kmW (thousend of mW) limit!!!
> I drive with a reasonable waveform both the qrp TX and
> medium power TX (and now the halfbridge tx) with an IXDD614 chip.
>
> Will resist still in this microwaves area waiting that the oter folks
> go to DC ;-)))
>
> CU Marco
>
> ----Messaggio originale----
> Da: dead.fets@gmail.com
> Data: 2-giu-2017 15.14
> A:<rsgb_lf_group@blacksheep.org>
> Ogg: Re: R: LF: Re: I: Fw: For today the FETs survived...
>
> Hello Marco,
>
> My  loading coil drifts as it warms up, but that's only when a kW or so
> is  run,  not  at  low power. But I think you are testing into a dummy
> load?   I  also had a poor drain waveform on one side of my push pull
> Class  "D",  that  was  only cured by changing one of the 2 FET's (that
> tested  fine  out  of circuit). We "microwavers" are old school now
> that
> people are moving to DC toggled every hour or so ;)
>
>
>
> Friday, June 2, 2017, 2:00:07 PM, you wrote:
>
>    
>> Hi Alan,
>>      
>    
>> and thanks for joining :-)
>> it's hard to believe at this stage that is correct to speak of "high
>> currents"..
>> The PA is an half bridge like
>> Andy's 700W but now I'm testing at low voltage: I see these problem
>> trepassing the 30Vdc supply level (and power is about 15W)..
>> Anyway will try with the "pulse rated caps" you suggested just in
>>      
> case
>    
>> my "low current" "low tension" ideas are wrong.
>> 73 Marco
>>      
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