Mirage B3016

Mirage B3016

Preamp Replacement
Back at the end of 2000, I saw a posting in rec.radio.amateur.equipment by a fella that had lost all the "smoke" in the preamp of his Mirage B3016 2 Meter amplifier:
Newsgroups: rec.radio.amateur.equipment
Message-ID: <t22h1mk3e2nq61@corp.supernews.com>

This was an area where I had done a wee bit of messing around -- so, I replied to the thread -- which is replicated here with some editing (for spelling and clarity) and an updated URL:
From: Jonesy W3DHJ
Subject: Re: Help, I blew my preamp... :(
Newsgroups: alt.ham-radio.vhf-uhf, rec.radio.amateur.equipment
Date: 2000-11-27 11:11:37 PST 
On Sun, 26 Nov 2000 22:16:49 GMT, Dan K Nelson wrote:
>"Gerry" <ka1stz@yahoo.com> wrote:
>>Is anyone familiar with the preamp circuit in Mirage amplifiers? I have
>> a model B3016 (2M, 30 in, 160 out), and I blew the preamp last night.
>> Thanks! -Gerry KA1STZ
>There are a pair of MPS-2222 transistors used in the preamp stage.
Nope -- the 2 MPS-2222 (or MPS-A13 on the schematic) are general
purpose xistors, and are used in the B3016 to drive the 'change-over'
relay and to drive the 'switch-in-the-preamp' relay.

The preamp is a J309 -- and just a handful of components (as the
original poster noted.)

I have the B3016. I was somewhat unhappy with the preamp's
performance. I scraped off all the preamp's components and
installed a Hamtronics LNY-146 on some short stand-offs over
the same piece of real estate where the original preamp had been.

http://www.hamtronics.com/lny.htm

For $29 you get 0.6 dB nf and 18 dB gain.

HTH es 73,
Jonesy
--
Marvin L Jones     | jonz         | W3DHJ  | OS/2
Gunnison, Colorado |  @           | Jonesy | linux __
7,703' -- 2,345m   |   config.com | DM68mn         SK
From: Jonesy W3DHJ
Subject: Re: UPDATE on Mirage B3016 preamp
Newsgroups: alt.ham-radio.vhf-uhf, rec.radio.amateur.equipment
Date: 2001-02-12 09:44:53 PST 
On Mon, 12 Feb 2001 12:36:50 GMT, Gerry wrote:
> Thanks to all that offered suggestions concerning my preamp. I liked
>the sound of Jonesy's suggestion (W3DHJ), which was to yank all the preamp
>components on the original board and wire in a hamtronics preamp. Well,
>that's what I did, and it's fantastic. I installed it in the amp box last
>night and tested it on the bench, then installed it on the tower today and
>tried it out for real. Awesome results! You have got to love that kind of
>gain! 73 de KA1STZ Gerry
I am very, very glad it worked out so well for you! Congratulations.
I don't get to use the preamp much, myself. I live in town and lots
of nearby 'stuff' overloads it too easily.
But, it sure kicks butt when I take it mountain-topping!

73 es gl,
Jonesy
--
 | Marvin L Jones     | jonz         | W3DHJ  | OS/2
 | Gunnison, Colorado |  @           | Jonesy | linux __
 | 7,703' -- 2,345m   |   config.com | DM68mn         SK
Maybe you recognize the old format.   HI!HI! ~~~~
UPDATE: SEPT'06:  We have pictures!
2M pre-amp
You can see here (and below) how the preamp is mounted on a threaded (metal) spacer -- to enable it to clear the relay and the wiring on the big PC board underneath it.

I used only one threaded stud -- the one you see here on the end/edge. It was simply expedient to do so. Rest assured, I won't obsess about it. HI!HI! I used inside star washers under the screw on top and under the spacer where it screwed to the big PC board.

The intent is to use the metal spacer as the DC path to ground.

(My only 'mobile' use of the Mirage amp is while rover'ing in the June, July, and Sept. VHF contests. The rest of the time it is used in the shack. If your use is primarily mobile, you might want to consider additional precautions against vibration problems.)

The +12V power connection on the preamp is conveniently located right at the preamp ON/OFF switch.
2M pre-ampThe RF connections are made with RG-174 coax.

The preamp board came with RCA "in" and "out" connectors - which I removed. I soldered the center conductor and the braid of the coax jumpers directly to the proper points on the preamp board. Likewise, I soldered the coax jumpers to the proper points on the big PC board.

In the picture to the left you can see a little better the real estate under the preamp board. This is where the original Mirage preamp was.

I removed all the original Mirage preamp parts.

A Hamtronics LNY-146 board image is here.
I have no association with Hamtronics other than this one purchase from them. You must realize, of course, that price above is from back in the year 2000.

UPDATE: JUN'07: It looks like Hamtronics no longer sells the LNY-series of preamps. (The 2 links above are via The Wayback Machine at www.archive.org.) However, the LNK-series look similar. But, I don't see an option to just buy the 'bare-board' preamp. Looks like they are selling the preamp, an aluminum box, and 2 BNC connectors for more than twice the price of their old LNY-preamp. In fact, if you click on and study the LNK-image, you may reach the same conclusion as I did: That is the LNY-bare-board inside their "$50" aluminum box. sigh...

I know nothing at all about other 2M Mirage or Mirage-like amplifiers, and whether or not this modification would work for any of them. As well, Hamtronics makes preamp models for 220 Mcs. and 450 Mcs., and there are Mirage and Mirage-like amplifiers for those bands, too...

And, I don't doubt that other folks make bare-board preamps, in either assembled and/or kit form, which might also Fit The Bill in this circumstance.

Feedback, if any, would be added here -- with attribution.

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Last updated: 10-Aug-08 		Document made KompoZer