From k5xu at comcast.net  Mon May 12 06:50:18 2025
From: k5xu at comcast.net (Mike Duke, K5XU)
Date: Mon, 12 May 2025 05:50:18 -0500
Subject: [AMRadio] Another one bites the dust
Message-ID: <000001dbc32b$a7787120$f6695360$@comcast.net>

I have occasionally bought parts and a few gadgets from this company, mostly
computer pieces, but apparently not often enough to keep them afloat.

 

The following is from their website:

 

"Marlin P. Jones & Assoc. Inc.

Company Closed 05/09/2025. All Rights Reserved."

 

 

Mike Duke, K5XU

 


From wn2ami at gmail.com  Mon May 12 13:36:08 2025
From: wn2ami at gmail.com (Rj Mattson)
Date: Mon, 12 May 2025 13:36:08 -0400
Subject: [AMRadio] That Bites me too Fwd: AMRadio Digest, Vol 238, Issue 1
In-Reply-To: <mailman.26.1747065615.24441.amradio@mailman.qth.net>
References: <mailman.26.1747065615.24441.amradio@mailman.qth.net>
Message-ID: <CAJsCO2gxG9kSUZW9bjPMiGxV9-taCVaS=vdLL-QqjaWunar3eQ@mail.gmail.com>

I remember buying an arc5 surplus xmtr from MPJ in the early 1960s.
Before the internet, I would get a hefty flyer from them.
I wish now I would have bought more from their internet site.
What are your favorites now?
Be well,
bob... w2ami x wn2ami 1962
Highland NY


.
   1. Another one bites the dust (Mike Duke, K5XU)

---------- Forwarded message ----------
From: "Mike Duke, K5XU" <k5xu at comcast.net>
To: "'AM Radio List'" <amradio at mailman.qth.net>
Cc:
Bcc:
Date: Mon, 12 May 2025 05:50:18 -0500
Subject: [AMRadio] Another one bites the dust
I have occasionally bought parts and a few gadgets from this company, mostly
computer pieces, but apparently not often enough to keep them afloat.

The following is from their website

"Marlin P. Jones & Assoc. Inc.

Company Closed 05/09/2025. All Rights Reserved."

Mike Duke, K5XU




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From mjcal77 at yahoo.com  Mon May 26 14:55:52 2025
From: mjcal77 at yahoo.com (CL in NC)
Date: Mon, 26 May 2025 18:55:52 +0000 (UTC)
Subject: [AMRadio] SX100 with added product detector
References: <1761958573.822538.1748285752294.ref@mail.yahoo.com>
Message-ID: <1761958573.822538.1748285752294@mail.yahoo.com>

I picked up a SX100 MK1 not a MK1A, and found an extra tube that turned out to be a product detector, added in a spot directly under the notch pitch shaft at the front panel.  Did some looking around to see if there was an old ham mag article about this but nothing found yet.  It uses a 6BE6 and is nothing like the one in the SX101, but it does work.  The design uses a multi-grid converter tube like in the SX101, but not the same one or circuit components, and it does not follow anything in the ARRL Handbook from around 1962 on where they used triodes.  The tube socket the builder used is a bit unique too, it is ceramic, with the tube solder lugs actually sandwiched in the ceramic exiting out the sides, with a central metal pedestal.   Anybody ever remember someone writing about designing this and installing in the SX100 series receivers?

Charlie, W4MEC in NC

From wb4am at yahoo.com  Tue May 27 13:32:46 2025
From: wb4am at yahoo.com (KD)
Date: Tue, 27 May 2025 17:32:46 +0000 (UTC)
Subject: [AMRadio] AMRadio Digest, Vol 238, Issue 3
In-Reply-To: <mailman.35.1748361613.25968.amradio@mailman.qth.net>
References: <mailman.35.1748361613.25968.amradio@mailman.qth.net>
Message-ID: <807723432.1018171.1748367166161@mail.yahoo.com>

? ? I know nothing really to make this comment, but is it possible the tube was added to improve on the quality of a ssb signal when the receiver was designed for AM?
? ? Please excuse my ignorance, I am really just curious, for the reason I am asking.?
73...



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Today's Topics:

? 1. SX100 with added product detector (CL in NC)


----------------------------------------------------------------------

Message: 1
Date: Mon, 26 May 2025 18:55:52 +0000 (UTC)
From: CL in NC <mjcal77 at yahoo.com>
To: amphone <amradio at mailman.qth.net>
Subject: [AMRadio] SX100 with added product detector
Message-ID: <1761958573.822538.1748285752294 at mail.yahoo.com>
Content-Type: text/plain; charset=UTF-8

I picked up a SX100 MK1 not a MK1A, and found an extra tube that turned out to be a product detector, added in a spot directly under the notch pitch shaft at the front panel.? Did some looking around to see if there was an old ham mag article about this but nothing found yet.? It uses a 6BE6 and is nothing like the one in the SX101, but it does work.? The design uses a multi-grid converter tube like in the SX101, but not the same one or circuit components, and it does not follow anything in the ARRL Handbook from around 1962 on where they used triodes.? The tube socket the builder used is a bit unique too, it is ceramic, with the tube solder lugs actually sandwiched in the ceramic exiting out the sides, with a central metal pedestal.? Anybody ever remember someone writing about designing this and installing in the SX100 series receivers?

Charlie, W4MEC in NC


------------------------------

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End of AMRadio Digest, Vol 238, Issue 3
***************************************
  

From mjcal77 at yahoo.com  Sat May 31 21:35:46 2025
From: mjcal77 at yahoo.com (CL in NC)
Date: Sun, 1 Jun 2025 01:35:46 +0000 (UTC)
Subject: [AMRadio] WB4AM product detector answer
References: <774730643.1935074.1748741746250.ref@mail.yahoo.com>
Message-ID: <774730643.1935074.1748741746250@mail.yahoo.com>

Well, there is a lot of info on the web on the science and reasons for product detectors, some including more math than you want to deal with.  I believe the plus side to the PD is that with an AM/CW basic design receiver and a simple diode detector,  you will notice that a strong SSB of CW signal may not demodulate properly since you don't have enough BFO signal for the level of the incoming RF.  Most times, the AVC in an AM receiver has to be turned off and the gain controlled by the RF gain pot in order to maintain a balance between the BFO sig and the incoming SSB RF, the same for CW.  The SX101 uses a multigrid  6BY6 as a PD, an in this SX100, the builder used a 6BE6.  The circuits are similar, but the components are greatly different.  Pretty sure he copied the SX101 set up, and tie in points.  Where he came up with this exact circuit is unknown, and his changes to the 6BJ7 circuit in order to tie it all in without the use of an extra wafer on the function switch was pretty ingenious.  It did make it fun to trace out all the wiring to figure out what the builder did though.

Charlie, W4MEC in NC

