May be Mal
But once again Jim has the answer to this problem ..if you can find
his articles after Google trashed the uk500khz news group ,
I think Jose R predicts a 6 dB gain by changing to PSK from the
Opera on/off keying but that would prevent most of the LH/MF usage
G..
--------------------------------------------------
From: "mal hamilton" <[email protected]>
Sent: Monday, September 10, 2012 6:13 PM
To: <[email protected]>
Subject: Re: LF: Re: Re: Re: DK0SWF antenna
Wolf
Overall considerations, Data modes that need Linear amps are very
inefficient. It is preferable to choose modes that use C, D or E
amplifiers like CW or QRSS one level demodulation. Two level might be a
consideration like OPERA.
Linear AB2 etc 40% efficient, class D or E 90% . It is the same with SSB
that needs a linear amp whereas CW with a class D is way ahead at 90% plus
efficiency.
mal/g3kev
----- Original Message -----
From: "wolf_dl4yhf" <[email protected]>
To: <[email protected]>
Sent: Monday, September 10, 2012 3:44 PM
Subject: Re: LF: Re: Re: Re: DK0SWF antenna
Hello Christian,
I have a few MOSFETs type HUF 75343 P3 to donate... they are 75 A, 55 V,
and Rds_on = 9 mOhm.
Only disadvantage is a relatively large gate capacitance, but despite
that they work reasonably well in my MF PA (in linear mode, with very
low impedance drive). I originally used them in my LF transverter, where
I never managed to kill any. Despite their "270 Watts" dissipated power
rating they need good cooling when operated in linear mode.
HW ?
73,
Wolf DL4YHF
(QRL: Bünde, not very far from you...)
Am 10.09.2012 00:03, schrieb C. Groeger:
> Hello Stefan,
> Sorry, my tx broke down, I had to stop.
> You were here 599 as strong as Wolf df0wd who is my mf neighbour!
> I'll Call you again next week with new mos fets...
>
> 73
> Df5qg
>
> Christian Groeger
>
> Stefan Schäfer <[email protected]> schrieb:
>
>> I'll join in too, soon. My temporary MF grabber is at
>> http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_MF_Grabber.html,
>> active during i am active...
>>
>> 73, Stefan
>>
>> Am 09.09.2012 21:24, schrieb C. Groeger:
>>> Ok, mal...give me 10 minutes, I'll be there!
>>>
>>> Christian Groeger
>>>
>>> mal hamilton<[email protected]> schrieb:
>>>
>>>
>>>> Christian
>>>> Looking out for you at present on 472.5 but nil hrd so far. Just had
a QSO
>>>> with DF0WD
>>>> 73 De mal/g3kev
>>>>
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