Bias is 500mA pr module; IMD3 has not been measured, but reports on the band
have been uniformly good.
More than 2000 QSOs have been made so far with this amp. Only mishap was
during an F2 opening to NA in 2001, when i forgot to reduce TCVR output to
20W, I still made 4 and a ½ QSOs before things went avry (12 of 16 IRF510
blew loudly and smelly) These were quickly replaced (at less than 30c a
piece!) and no one ever commented on the output, despite the vast overdrive.
Vy 73 de OZ1PIF, Peter
********** OZ1PIF **************
email: oz1pif(no-spam-filler)@privat.dk
http://home24.inet.tele.dk/oz1pif/
Ph. +45 4619 3239
Snailmail:
Peter Frenning
Ternevej 23
DK-4130 Viby Sj.
Denmark
***********************************
----- Original Message -----
From: "Carcia, Francis A HS" <francis.carcia@hs.utc.com>
To: "'Peter Frenning [OZ1PIF]'" <oz1pif@privat.dk>
Sent: Thursday, April 07, 2005 2:34 PM
Subject: RE: [Amps] Transistor amp's
> Hi Peter,
> Very GOOD JOB! What current do you bias the stages to get a clean AB1 and
> do
> you know
> third order distortion level. fc WA1GFZ
>
> -----Original Message-----
> From: Peter Frenning [OZ1PIF] [mailto:oz1pif@privat.dk]
> Sent: Thursday, April 07, 2005 8:26 AM
> To: Carcia, Francis A HS
> Subject: Re: [Amps] Transistor amp's
>
>
> Francis et al.
>
> The configuration is 4 + 4 IRF510 in push-pull to give 250W, and two such
> modules are then combined to give the 500W (could as easily have been 4 to
> yield 1KWor six for 1.5KW), efficiency is just under 60%, 40V at 10A for
> 250W
>
> The combiner used is a simple 1/4lambda combiner made from 75Ohm Coax.
>
> The end result is then passed through a low loss LP filter with an extra
> 70dB notch at 2nd harmonic and 85dB at 3rd.
>
> Vy 73 de OZ1PIF, Peter
>
> ********** OZ1PIF **************
> email: oz1pif(no-spam-filler)@privat.dk
> http://home24.inet.tele.dk/oz1pif/
> Ph. +45 4619 3239
> Snailmail:
> Peter Frenning
> Ternevej 23
> DK-4130 Viby Sj.
> Denmark
> ***********************************
>
> ----- Original Message -----
> From: "Carcia, Francis A HS" <francis.carcia@hs.utc.com>
> To: "'Peter Frenning [OZ1PIF]'" <oz1pif@privat.dk>
> Sent: Thursday, April 07, 2005 2:08 PM
> Subject: RE: [Amps] Transistor amp's
>
>
>> Peter,
>> How did you configure the 16 FETs.
>> I have 14 IRF840s push pull parallel class e on 160 meters
>> and 22 FAQ11N90 push pull parallel on 75 M. The 75 M rig will hit 5KW
>> peak
>> out 1 KW carrier.
>> 50 MHz that is very interesting! fc
>>
>> -----Original Message-----
>> From: Peter Frenning [OZ1PIF] [mailto:oz1pif@privat.dk]
>> Sent: Wednesday, April 06, 2005 5:05 PM
>> To: amps@contesting.com; Philip de Cadenet
>> Subject: Re: [Amps] Transistor amp's
>>
>>
>> I have in fact built a 500W 50MHz amp using 16xIRF410, they have about
>> 15dB
>> gain at 40V supply, and are relatively clean in AB1
>>
>> Vy 73 de OZ1PIF, Peter
>>
>> ********** OZ1PIF **************
>> email: oz1pif(no-spam-filler)@privat.dk
>> http://home24.inet.tele.dk/oz1pif/
>> Ph. +45 4619 3239
>> Snailmail:
>> Peter Frenning
>> Ternevej 23
>> DK-4130 Viby Sj.
>> Denmark
>> ***********************************
>>
>> ----- Original Message -----
>> From: "Philip de Cadenet" <phil@transmittersrus.com>
>> To: <amps@contesting.com>
>> Sent: Wednesday, April 06, 2005 6:38 PM
>> Subject: [Amps] Transistor amp's
>>
>>
>>> Bill,
>>>
>>> Those Harris modules use inexpensive switching FET's, probably IRF
>>> series.
>>>
>>> The problem is, you're not going to see much out of them on 10m!
>>>
>>> However, I do know someone using them on the FM broadcast band but not
>>> with little in the way of efficiency.
>>> --
>>> Philip de Cadenet G4ZOW
>>> Transmitters 'R' Us
>>> http://www.transmittersrus.com
>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>>
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>>>
>>>
>>
>>
>>
>> --
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>> _______________________________________________
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>>
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>>
>
>
>
> --
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