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Friday, December 30, 2011

Back to the Barebones (Receiver)

My rehabilitation of homebrew 17 meter gear from the last solar cycle continues. Following the same path that I followed in 2001-2002, I will now move from DSB to SSB. I pulled out the little receiver that I put together way back when. It is a version of Doug DeMaw's "Barebones Superhet" (aka "Barbados Superhet"). I bought it on the net. It had been put together by a skilled builder on a FAR Circuits board. The fellow who built it had changed the IF from Doug's original color burst freq (3.579 MHz) to 5 MHz. He had also put in a varactor controlled VFO using a DC voltage multiplier to get more voltage variation across the varactor. I also think he had it built for 20 meters.

I converted it to a 17 meter receiver. I put in a VXO, using two crystals controlled by a panel switch. I also changed the caps in the filter so as to broaden the response for SSB.

As I was going through all these modifications, I turned to the USENET for help and advice. Dale, W4OP, came to my assistance. Little did we know how DETAILED his familiarity with my RX was:

"Bill N2CQR MOHBR" ...@virgin.net> wrote in message

news:22f6e3ee.0503292244.1b9a1481@posting.google.com...

> Dale: Wow, another Barbados RX builder. That was my first successful
> superhet project. I now have the one I built (still on 20), and this
> morning
> I got another one (the one built by someone else on a factory-made
> board)going on 17 with a VXO. I have a THIRD partially built Barbados
> RX board. If this
> keeps up, I'll soon have a BBRX museum.
>Hi Bill,

Did I sell you mine years ago? I seem to recall using a temp stabilized
varicap in a shielded enclosure for main tuning. It was done on a factory
board. Or was that a 6M xverter I sold?

Dale


Newsgroups: rec.radio.amateur.homebrew
From: meara.lon...@virgin.net (Bill N2CQR MOHBR)
Date: 30 Mar 2005 22:33:57 -0800
Local: Thurs, Mar 31 2005 1:33 am
Subject: Re: Homebrew projects
Dale: Wow, small world! Yea I think that is the one I'm working on. I think
you also had a DC-DC converter to bring the voltage to the varicaps up.
Very nice enclosure for the oscillator. I now have it percolating nicely
as a VXO around 23 Mhz (for the 17 meter band). Bill

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1 comment:

  1. Wouldn't that be the "Bare-bados"?

    73.......Steve Smith WB6TNL
    "Snort Rosin"

    ReplyDelete

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