Envelope-to: dave@picks.force9.co.uk Delivery-date: Thu, 02 Feb 2006 13:56:21 +0000 Received: by ptb-mxcore01.plus.net with spam-scanned (PlusNet MXCore v2.00) id 1F4ewc-0002t8-Uk for dave@picks.force9.co.uk; Thu, 02 Feb 2006 13:56:20 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore01.plus.net with esmtp (PlusNet MXCore v2.00) id 1F4ewc-0002sY-NC for dave@picks.force9.co.uk; Thu, 02 Feb 2006 13:56:18 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1F4ew7-000480-1t for rs_out_1@blacksheep.org; Thu, 02 Feb 2006 13:55:47 +0000 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1F4ew6-00047r-7d for rsgb_lf_group@blacksheep.org; Thu, 02 Feb 2006 13:55:46 +0000 Received: from rwcrmhc14.comcast.net ([204.127.192.84]) by relay2.thorcom.net with esmtp (Exim 4.51) id 1F4feN-0001tN-Sk for rsgb_lf_group@blacksheep.org; Thu, 02 Feb 2006 14:41:34 +0000 Received: from AIRPORTTERMINAL (c-67-177-102-19.hsd1.ct.comcast.net[67.177.102.19]) by comcast.net (rwcrmhc14) with SMTP id <20060202135453m14005688re>; Thu, 2 Feb 2006 13:54:58 +0000 Message-ID: <001b01c62802$9941a6a0$6901a8c0@AIRPORTTERMINAL> From: "Jay Rusgrove" To: rsgb_lf_group@blacksheep.org References: <000201c627fa$e6299570$e6a4c593@RD40002> Date: Thu, 2 Feb 2006 09:11:39 -0500 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Subject: LF: Re: RE: Re: J310 IMD figures Content-Type: text/html; charset=windows-1252 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SpamFiltered: by PlusNet MXCore (v2.00) Content-transfer-encoding: 8bit

Jim

Sorry...probably should have used 'attenuation' instead of 'gain'...

In order to be consistent I used the same method as the original article:

http://www.arrl.org/tis/info/pdf/0109031.pdf

"Test signals were fed through a 12-pF capacitor to simulate the source impedance of a 1-meter whip. Referenced to the antenna output, the following values were measured..."

Jay

----- Original Message -----

From: james moritz

To: rsgb_lf_group@blacksheep.org

Sent: Thursday, February 02, 2006 8:16 AM

Subject: LF: RE: Re: J310 IMD figures

Dear Jay,

How is the -16dB “gain” defined?

Cheers, Jim Moritz

73 de M0BMU

-----Original Message-----
From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Jay Rusgrove
Sent: 02 February 2006 12:54
To: rsgb_lf_group@blacksheep.org
Subject: LF: Re: J310 IMD figures

Roelof

Had an opportunity to build 6 of the Amrad CP666 e probes (for a military customer) a while back and measured the following. First column is measurments from the QST article, second column is measurment average of the 6 antennas built (all measured within a dB or so of each other), third column Amrad circuit with single J310 at 12 volts and fourth column single J310 at 24 volts.

Measured significantly higher IP2 than the original article leading me to believe there might have been a measurement error in the original article...or I got a batch of CP666s that were unusally good performers. The fact that the J310 at 12 volts achieved +50 dBM makes me lean toward possible measurement error in the original article.

Hope these columns stay lined up when passing through the reflector!

                      Amrad article         W1VD built           J310 12volt       J310 24 volt


1 dB comp.    +25 dBm                +25 dBm            +17 dBm            +18 dBm

IP2                +53 dBm*              +60 dBm             +50 dBm           +60 dBm

IP3                +37 dBm                +36 dBm             +32 dBm          +32 dBm

Gain              -16.7 dB                 -16.5 dB               -10 dB              -10 dB

* possible measurement error

Jay, W1VD