Message-ID: <CB6F077431AF4E8798025422B7631C65@gnat>
From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
References: <159c6d4aa99-2cc9-11356@webprd-m36.mail.aol.com>, <58864091.2070406@posteo.de>, <Pine.LNX.4.64.1701231809200.12384@plato.ucs.mun.ca> <588A62AE.2358.E190C0@roelof.ndb.demon.nl> <Pine.LNX.4.64.1704062117500.25510@plato.ucs.mun.ca>,<Pine.LNX.4.64.1704081152460.543@plato.ucs.mun.ca> <MWHPR1101MB20779803DDD021FE873B0BBECF0F0@MWHPR1101MB2077.namprd11.prod.outlook.com>
Date: Sat, 8 Apr 2017 18:47:10 +0100
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Subject: Re: LF: QRSS10 477.7 kHz/New TX
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Hi Joe and Laurence, It depends what power you design for, there can be 
ahell of a lot of current flowing through it .....I remember measuring 12A 
running100W or so. I had this current fusing the connection between some od 
the capacitor foil and the lead wires, hence the suggestion of "pulse rated" 
caps for C1 and C2.  I guess this might warm 0.5mm wire a bit. I am a 
believer in using the maximum supply voltage the Fets will stand and not 
trying to get everything to work off 12v !!

It's an age thing y'know :-))

Andy G4JNT and I are at a microwave do this weekend.

Alan
G3NYK
----- Original Message ----- 
From: "Laurence KL7 L" <hellozerohellozero@hotmail.com>
To: <rsgb_lf_group@blacksheep.org>
Sent: Saturday, April 08, 2017 4:11 PM
Subject: Re: LF: QRSS10 477.7 kHz/New TX


Joe - the warmness of the air coil was questioned with the author a few 
years ago when I built a few uep's whilst operating in 9V1 - no issues just 
a little heat which may be a concern if vfo etc was in the same enclosure.

no sign of your sig down here this time in XE - just too noisy at the moment

73 Laurence KL7L/XE. el60

> On Apr 8, 2017, at 10:07 AM, "jcraig@mun.ca" <jcraig@mun.ca> wrote:
>
> On Tuesday a new tx (gw3uep design) was built and worked very well.
> An IRFP140, sm capacitors and 1mm wire was used although L2 (7uH)
> beacme quite warm.  The 1 uF  caps (type unknown... yellow and stamped BEC 
> C11C) did their bypassing without complaint.
>
> Roelof had an O copy on yesterday morning (the 7th) during the
> first on the air test.
>
> G4JNT Andy's explanation of how the reactances are absorbed by the
> L network which brings the drain impedance to 50 ohms is enlightening.
> Is there a way to find impedance at the drain or is this just the
> R value on Alan's G3NYK Class E spreadsheet?
>
> The new TX will be on again 9 Apr. 0000-0900 utc
>
> Hopefully this design will be merciful on FETs.  If not, there's a
> 3-500 waiting on the shelf.
>
> 73's
> Joe VO1NA
>