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SST-20 from Wayne Burdick, N6KR - Manhattan Circuit Construction Madness Project
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Hello gang,
I was talking to a mentor (Elmer) that I have been talked to many times in the past.? Well, there are many Elmers on this group because this group is a goldmine of great projects and advice.? Anyways, he suggested that the 2N2/40+ might be too complex for me which I had a feeling it was.? This is why the 2N2/XX was way down on my bucket list.? However, he did say when I do build a 2N2/XX, that I should build the original 2N2/40 from that QRPp article using Manhattan Construction and use all discrete parts like it suggests.
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The mentor suggested I try with an easier radio to build as a Manhattan Construction - SST-20 which is mentioned in a message by Chuck Adams aa7fo:
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Chuck also mentioned a need to replace the Op Amp.? And get permission from the author.
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If Chuck or someone knows more about this SST-20 or knows where some manual, schematic is for it, please let us know.? I try not to step on Chuck's toes here.? I just realized I needed to start on a project for my level of experience.
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73 Daniel KK4MRN
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Jerry,
Chuck wants to get permission because the SST-20 is copyrighted - the radio design - manual - schematic. So, out of respect for Wayne - both were originally part of NorCal Club. So, whatever the updated design they come up with, they want to get permission to post the design on the web.? When I say "they", I am talking about Chuck and anybody else that helps redesign the SST-20 to use a different op-amp.
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Never know, Chuck may even want to do something like he did for the NorCal 40A 25th anniversary and create Gerbers for a PCB.? But i doubtful on that since his post was about Manhattan Construction.?? Manhattan Construction or even point-to-point construction really causes you to think about wiring up your components compared to plugging your parts in a PCB.?? I think it was Ashhar Farhan who said something you do not really learn much by stuffing a board in a kit, but you do by home brewing, ugly construction or Manhattan construction or point-to-point construction.? Maybe not the exact words. I maybe even got the attribution to the wrong person and I do apologize for that.? But the point is the same.
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Remember, nobody likes their work stolen or taken without permission.? And many people on the web seem to think every document on the web is a free for all.? Just like when software has an open source license - they think it simply means - free for all - it does not mean that.
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Just be respectful to the people who spent many hours or months or years designing or redesigning the SST-20 or NorCal 40A 25th Anniversary Edition or the documentation? videos showing how to build these radios.? Some people were very disrespectful and created kits and said they were not kits of this radio on ebay.? Included videos on a DVD of someone showing how to build this radio.? Included documentation on how to build this radio.?? And course, did all of this without permission ignoring any copyrights - disrespecting the people who redesigned the NorCal 40A for the 25th anniversary to fit on a 100mm x 100mm pcb to take advantage of thos pcb specials like jlcpcb.? Take videos and documentation too without permission and selling it.?
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All disrespectful.
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This is why Chuck is doing this - he wants to be respectful to Wayne Burdick - and so do others on the QRPTech group.
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73 Daniel KK4MRN
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Hmmmm
Once I find a schematic on the internet or some publication, it's fair game for me to replicate it
in whole or part.? Period.? Take a look at my QRZ page and see all those stolen designs!? ?Heck I
even have Rick Campbell's and Roy Lewallen's autographs on a couple of purloined schematics.?
Says Rick, ".....I'm honored that you built this....".
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That said, republishing and assembling kits for a group build might be different...but if that schematic shows
up in the wild west of the internet, I can build it, in whole or part, using my own construction methods.
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Furthermore, I can change/alter/modify any found design to suit my hearts content.? Another word for that:
"home-brewing".
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Jerry W
KI4IO
Warrenton, VA |
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Daniel
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Interesting. I imagine the copyright is to disallow someone from commercially selling that manual or large portions of it, likely with a kit.?
QRP rigs are published to encourage experimenters to built them.?
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The SST strikes me as a rig one will actually enjoy operating, a bonus. Enjoy your research replacing the op amp. If you publish the modified design say in a qrp journal, it's a courtesy then to contact original sponsor or designer. Often the editor may join you in that. To merely describe it here or on the web, not necessary.?
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Curt wb8yyy?
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Curt, I think you and Jerry are correct that in general most do not care if hams home brew the radios of other designs and show them off.? They even encourage it.? Ashhar Farhans uBitx transceiver for example, he encourages others to home brew it.
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But what you said Curt is right to the point - commercially selling the manual or boards or kits is disallowed unless you get permission.? i see qrp guys stuff on ebay even though qrp guys says they do not sell their stuff on ebay.?
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When I brought up the topic of SST, I really wished i did not say anything about asking permission from the author.?? I do not want to cause any difficulty on here.
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73 to Curt and Jerry from Daniel KK4MRN
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Daniel -?
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There are cheap unauthorized knock-offs of QRPGuys' designs on eBay. That is probably what you are seeing, unless you're seeing ads for people selling their genuine gear from QRPGuys.
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It's frustrating when someone puts the hard work in to come up with a product, then someone else steals that work and uses it for their own profit. Unfortunately, a lot of these sellers are overseas, and legal action is either not possible, impractical, or simply not worth it.
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Dave
AA7EE |
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Daniel
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All is well. Looking forward to you building an SST or something to your liking. Examine AA7EE projects for inspiration, I recall he describes all the details. If you build a modern SST I anticipate Wayne himself will be thrilled when you email him. Your among one of the most close-knit communities in ham radio. Email me if you find a show stopper toward building an sst.?
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Curt
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I finally searched for Dave AA7EE blog site and yeah, wow - that is a beauty.
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Dave has a link to another SST where JH1PJL switched out the LT1252? for 2SC1815 for the driver and a 2SC799 for the PA.?
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I think Chuck swapped out for a TI TL592 but HE would prefer a transistor, fet, or darlington.
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I do have those transistors used in kitsandparts 5Watter which is the 2SC5706.? I should buy more of those 2SC5706 but they do get hot i read so they need a heat sink.?
And I have 2N3553 as well.? Of course, since I have parts for the NorCal 40A...
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Daniel
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The output power depends upon bias voltage and the impedance presented to the output of the final. If this transistor directly feeds the low pass filter, at 12-13 volt bias it will provide 1.5 to 2 watts. To obtain more from a signal transistor requires a transformer, and of course also a beefier transistor. Yes examine the design of the 5 watter to see if it contains a transformer as it should require it. Note the increased output power requires a more robust TR switch. Best to heat sink any final stage device you employ.?
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I had forgotten the op amp was used in the transmitter. Of course it has to provide a robust output. Most classic designs do use a transistor here and often a transformer between it and the final amplifier. Wayne was being creative to use a then available op amp to simplify things. I could dig to see if I have one here or network on alternatives. The SST does look like a modified SW-20. Another variation on the SST arrangement is the 4state Cyclone design, but different device technology for the PA that also serves as first mixer on receive. The SST may be the best fit for simpler Manhattan construction.?
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Curt
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Re; SST transceivers, for those considering a homebrew version: For my 20m SST, I made several worthwhile mods: 1.? I added a JFET amplifier after the crystal filter feeding into the '603 product detector per NA5N's circuit in his Homebrewer's Handbook. ? ? ?Not so much for additional?RX gain; it does decrease the NF a bit. 2.? Added a second tuned circuit after the '602 transmit mixer. This used a T30-6 mounted below the board where pins 4 and 5 were located and ? ? ?small diameter wires connecting the?inductor to a very small variable?capacitor (30 pF 4mm) mounted on top of the board towards the centre of the board ? ? ?between the '602 and LT1252, with a small NP0 or C0G, 2.5 mm LS, to bring?it to resonance. The existing 5 pF NP0s seemed to work OK in creating the ? ? ?needed BP. 3.? For the crystal filter, changed to 220 pF coupling capacitors between the crystals and changed the in and out L networks to 22 uH and 56 pF, per K8IQY's ? ? ?version of his 10m Iowa SST, as in QRPp.?The lower filter impedance gives a bit sharper filter; his (K8IQY's) filter uses the same 3.932 MHz (nominal) ? ? ?crystals as the 20m version. 4.? For the VXO, adding a small value NP0 or C0G (~2p2 - 5 or 6pF) will increase the tuning ranging. One might also mount an axial RFC vertically in the ? ? ?original ?VXO's RFC and add a smaller?value in ?series to extend the tuning range downward. It will get to the point that the JFET oscillator voltage ? ? ?decreases at the low end; that's how you'll it's gone too far. 5. The early WR SST boards had through holes?for a capacitor near the AF gain control. Adding a capacitor?(~ 10-15 uF electrolytic?or tantalum) will roll off? ? ? ?some of the HF audio nicely; 22uF was too much (decreased the desired AF signal). If you're homebrewing?an?SST, any of the above can be implemented in your layout. It took a little foresight to make the above changes on an SST PWB. IF anyone's interested in the above mods, I can remove the covers and write down the exact component values I used for the 20m version. Regards, Walt ?K3ASW On Mon, Mar 17, 2025 at 11:10?PM Curt via <wb8yyy=[email protected]> wrote:
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