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In the spirit of "legacy" QRP rigs as mentioned by Chuck Adams AA7FO recently in his "Manhattan Circuit Construction Madness" post, I have decided to build a 2N2/40+ Transceiver designed and built by Jim Kortge K8IQY. I am going to build my 2N2/40+ using the manhattan style construction technique for my Spring Project.
I am already having to scrounge for parts, lol.
2 MV1662 varactors that are used in the "Variable Xtal Filter" (D9, D10)
1 audio transformer, 1.2K ohm primary, 8 ohm secondary (T10)
Does anyone have a source they can point me to for these parts?
Keep the solder flowing! :)
73,
Alan, N8WQ
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For the audio transformer, Mouser has: 42TM003-RC That will work perfectly in the 2n2 rigs. When I built my version that was what I used and had no issues. It's still my favorite home-brew rig. 73 Mike M.? KU4QO
In the spirit of "legacy" QRP rigs as mentioned by Chuck Adams AA7FO
recently in his "Manhattan Circuit Construction Madness" post, I have
decided to build a 2N2/40+ Transceiver designed and built by Jim Kortge
K8IQY. I am going to build my 2N2/40+ using the manhattan style
construction technique for my Spring Project.
I am already having to scrounge for parts, lol.
2 MV1662 varactors that are used in the "Variable Xtal Filter" (D9, D10)
1 audio transformer, 1.2K ohm primary, 8 ohm secondary (T10)
Does anyone have a source they can point me to for these parts?
Keep the solder flowing! :)
73,
Alan, N8WQ
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Thanks for the part number Mike!
I will go ahead and order one plus some spares :)
Alan, N8WQ
On 3/14/25 11:39, Michael Maiorana via
groups.io wrote:
toggle quoted message
Show quoted text
For the audio
transformer, Mouser has:
42TM003-RC
That will work
perfectly in the 2n2 rigs. When I built my version that was
what I used and had no issues.
It's still my
favorite home-brew rig.
73
Mike M.? KU4QO
In
the spirit of "legacy" QRP rigs as mentioned by Chuck Adams
AA7FO
recently in his "Manhattan Circuit Construction Madness" post,
I have
decided to build a 2N2/40+ Transceiver designed and built by
Jim Kortge
K8IQY. I am going to build my 2N2/40+ using the manhattan
style
construction technique for my Spring Project.
I am already having to scrounge for parts, lol.
2 MV1662 varactors that are used in the "Variable Xtal Filter"
(D9, D10)
1 audio transformer, 1.2K ohm primary, 8 ohm secondary (T10)
Does anyone have a source they can point me to for these
parts?
Keep the solder flowing! :)
73,
Alan, N8WQ
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Are there any other hard-to-find parts in the 2N2/40+ Transceiver that has a replacement that can be found?
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It seems hams are gravitating (is this a real word) towards this radio to build Manhattan construction.? It is on my bucket list, but way down my bucket list because I figured I needed more build experience to build this.? But if I have built a NorCal 40B CW Transceiver kit and done some Manhattan construction like some blocks in Curt's transceiver, would I have the experience to build a 2N2/40+ ??? I do like the concept of building one block at a time.?
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Thanks,
Daniel KK4MRN
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Do you have the Winter 1998 issue of QRPp? It is a construction manual for the original 2N2/40 that Jim Kortge developed: broken down by subcircuits with tests, drawings by Paul Harden, parts list, and other tidbits.
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Must have.
--
William, k6whp
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"Cheer up, things could get worse. So I cheered up and things got worse."
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Just checked. It's in the files section -- along with the AZ Scqrpions' layout board and other tidbits. Here's the QRPp issue.?
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--
William, k6whp
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"Cheer up, things could get worse. So I cheered up and things got worse."
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Thank you!? ?I downloaded and created a new directory, 2n2xx.? ?That's a start.? ?Next step: Dive into my junque box of resistors, capacitors, diodes, transistors, crystals, pots, etc.? ?Not sure whether the xfmr will emerge, but who knows.??In the meanwhile, are their fixes and enhancement suggested by prior builders that I should add to my directory???Anyone else in for the challenge?
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I have a very fond memory of the Tooty-Too-Tooty-Too and its '2907 sibling.? ?Those, and '741 Op-amps, hex-inverters, and '555 timers.? ?Building analog filters and relay logic boards were among my first professional assignments as a newly-minted PSU EE at the then GE-HVDC Projects Operation in Philadelphia, 1969.? We didn't use copper-clad boards, rather rivets and a fiberglass matrix board on 0.1" centers.? All point-point wired.??
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Howard, n3fel
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Thanks for the transformer recommendation Mike. I'm currently assembling a 2N2/20 from a kit, but am hoping to do a 2N2 scratch build afterwards, if I haven't burned myself out by then! With that in mind, I bought 3 x 42TU400-RC from Mouser but was a little disappointed when they turned up, as they are bigger and heavier than the transformer used in the kit version. Will look into your recommendation.
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Alan - Dan's Small Parts and Kits has the MV1662. The ordering process is a bit of a pain, as you have to write out your order and mail it to him with a check or money order. It's worth calling him first, to ensure he actually has it, as sometimes he will substitute other parts without saying anything. Hopefully someone else knows of an alternative supplier for the MV1662, or has a suggestion for another varactor with similar properties.
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I'm planning on following the schematic of the Norcal version of the 2N2 for my scratch-build, as I figure it's the most optimized version. Mine doesn't have to be all 2N2222's. I even used a 3 terminal regulator device in place of the zener in mine *shock horror* :D I do plan on making the crystal filter in mine variable bandwidth, as in the 2N2/40+ though. I wish the kit version had that.
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I'll be following this, and other 2N2 threads, with interest.
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Dave
AA7EE
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If anyone is curious, I have all the data files on github for my take on the 2N2-40+ The VFO, BFO and Xmit signals are synthesized, the output amp is the now "traditional" trio of BS170, but the core of the receiver stays true to the original design.? All the Kicad files are there. If I were to build another one, I'd fix the few issues that I have with the original boards (which is outlined in the readme). Or maybe redesign the digital side for a more modern processor and abandon the Arduino Nano. Feel free to ask if you have any questions. Like I said before, it is my favorite home-brew rig.? Mike M.? KU4QO
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Hi Dave,
Thanks for the intel on Dan's Small Parts source for MV1662
varactors!
I am submitting an order on Monday.
"I even used a 3 terminal regulator device in place of the zener in
mine *shock horror*"
LOL, I might do something similar Dave, I already have "The K8IQY
Islander Amp" designed by Jim K8IQY that I built manhattan style on
6/26/13. It is the best sounding discrete amp I have ever built! I
might use it instead of the stock 2N2/40+ amp to save me a little
bit of time. I really should compare the circuits. Jim can chime in
on the details :)
73,
Alan, N8WQ
On 3/15/25 12:58, davidgeorgerichards
via groups.io wrote:
toggle quoted message
Show quoted text
Thanks for the transformer recommendation Mike. I'm currently
assembling a 2N2/20 from a kit, but am hoping to do a 2N2
scratch build afterwards, if I haven't burned myself out by
then! With that in mind, I bought 3 x 42TU400-RC from Mouser but
was a little disappointed when they turned up, as they are
bigger and heavier than the transformer used in the kit version.
Will look into your recommendation.
?
Alan - Dan's Small Parts and Kits has the MV1662. The
ordering process is a bit of a pain, as you have to write out
your order and mail it to him with a check or money order. It's
worth calling him first, to ensure he actually has it, as
sometimes he will substitute other parts without saying
anything. Hopefully someone else knows of an alternative
supplier for the MV1662, or has a suggestion for another
varactor with similar properties.
?
I'm planning on following the schematic of the Norcal version
of the 2N2 for my scratch-build, as I figure it's the most
optimized version. Mine doesn't have to be all 2N2222's. I even
used a 3 terminal regulator device in place of the zener in mine
*shock horror* :D I do plan on making the crystal filter in mine
variable bandwidth, as in the 2N2/40+ though. I wish the kit
version had that.
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I'll be following this, and other 2N2 threads, with interest.
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Dave
AA7EE
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Look what turned up in the "Magnetics" box! Howard, n3fel
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Hopefully, people do not mind me posting the link to our wiki page yet again.? Feel free to add more links.
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If a link is dead, update the link and mark it as dead. maybe the page is down. or the business is gone.? sometimes websites have redesign so old links no longer work.
And let us know if you find fakes or counterfeits or the parts turn out to be good.
Or you have good parts from an ebay seller - maybe not in the wiki, but at least in an email.
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As a homebrewer or qrp radio builder, we have to source our parts, so knowing where to get good parts is important - and knowing where to stay away from too.
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A recent link I updated was Surplus Sales of Nebraska. Their old default link no longer worked but I discovered their correct default link.
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By the way, there is a 2N2 discussion group on Groups.IO.? I posted a question regarding modification of a 600:600 transformer for use in the 2N2 output section.? I no longer need one but others might consider and comment.? ? I would guess that most folks there are also on this group, anyway.? Howard, n3fel
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Howard - that 2N2 group is intended mainly for discussion of the Norcal 2N2/XX kit. It would be great if there was a discussion group for 2N2 scratch builds but that doesn't seem to be the case. I doubt there would be enough interested people to make it a viable group.
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Dave
AA7EE
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Alan - I also built Jim's Manhattan Islander amp. I built it specifically to fit inside my Fort Tuthill 80, as that rig will only drive headphones. Unfortunately, I wasn't getting good fidelity from it, but I think that had more to do with how I was interfacing the Tut80 output with the input of Jim's amp. I'm keeping it in a box on the shelf, waiting for that moment when I need a neat little discrete audio amp. Oh, and Howard - it uses the same Radio Shack output transformer that you just found! I bought two of them when RS was going out of business, thinking that they might come in handy one day. I do have some misgivings about using one in my (hopefully) upcoming 2N2 build though. I don't know exactly why, but it's smaller and less physically substantial than the one used in the 2N2 kit. I've long felt a bit unsure about the quality of some of the parts from RS, though I don't know how warranted that is. I'm sure it'll be fine. I'm just being a worry wart.
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Here are a few quick shots of my little K8IQY amp, using the RS output transformer.
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Dave
AA7EE
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Alan N8WQ
k6whp
