Skip to main content

July 19, 2024. With a doff of the cap to VK3YE, Peter Parker.

VK3YE, Peter Parker has churned out a mountain sized number of projects that are a  three-fer. The Knobless Wonder is a great example where Peter has designed a 40M SSB transceiver that is a simple design, easy to build and works well (that's 3).

[Of note, if you are into DSB radios then VK3YE has the subject totally covered.]

In the 1st video where QSO's are being recorded VK3YE's has a terribly noisy environment as a routine challenge. The 2nd video was shot at the beach and thus you get a much better feel of how good this radio works.





Essentially Peter has a designed a 10 Transistor SSB transceiver whereby choosing the right crystals builds the Crystal Filter at the operating frequency (7.159MHz). So, no LO is needed, and the incoming signal is fed to the IF. Thus, no Knob needed for the main tuning dial ~ Knobless! Most of the supporting transistors are the BC458 (NPN) and the Driver and Final are BD139's.


VK3YE"s Knobless Wonder 




A Build from JA2GQP








The BFO can be set above or below to give you LSB or USB. True it is a one channel radio but so is FT-8. The closest frequency that I could find for non-SMT crystals two years ago at Digi-Key was 7.200 MHz but are now obsolete. Surface mount 40M crystals can be found at Mouser. The 7.2 MHz ten-piece price is 21 cents. They also have 7.168 and 7.1505 MHz in surface mount stocked. I also see non-SMT crystals at Mouser for 7.175MHz. (Short can)
 
Could this be an opportunity to build a match box sized SSB transceiver to be featured on Hackaday (bragging rights). Forget Hackaday as the lurker detractors would complain it only operates on one frequency. The 20M Color Burst crystals are on 14.318 MHz and lots of POTA stations operate near there. So that is another opportunity.
 
About two years ago I did buy from Digi-Key the 7.2 MHz crystals and so that might be an interesting prototype project for this winter. The BFR106, a very rugged surface mount device, looks like a good fit for use on a project like this. This could be the answer to the Michigan Mighty Mite! My twizzle on this project would be to change the IF Module from 4 transistors to two and using micro relays steer the signals in one direction through the filter.

A HB to HB QRP QSO


TYGNYB 

73's
Pete N6QW

 



 





Popular posts from this blog

January 26, 2024. A simple CW Transceiver/Transmitter

Cruise through the lower part of the ham bands bands and what do you hear? Well, FT-8 and CW. Often you will not hear any SSB stations yet go to the lower part of the bands, and it is a cacophony (I love that word) of bad sounding signals and some high-speed keying. Fast is not so much of the issue as is bad, run together and jerky keying. But none the less our hobby started there.    So, you could crank down your ICOM 7300 and watch the waterfall on CW or you could homebrew a radio. Actually, to do CW right you need more thought up front than you do with a SSB transceiver. Often, I will state that a CW Transceiver is much more difficult to build than a simple SSB rig. I published two articles in QRP Quarterly on CW transceivers and all I got was a yawn so maybe history will repeat itself.  Yawn!   30M CW Transceiver with RIT!   Of interest is that the LO is a Varactor tuned LC oscillator using a NE602. Look closely at the RIT circuit which is only activated on ...
Read more

March 31, 2024. Happy Easter to those who celebrate this day.

What a great day to Binge on Chocolate and experience the pain of that filling that has been leaking.  I would be in that category with the leaking filling(s) had I not just spent an amount equivalent to one of the fancy new uptown appliance box transceivers on two filling repairs. Well at least I can binge on the Chocolate bunnies without fear of pain. Regrettably everything appears to have jumped in price including the price of parts. Well not so much the parts as the shipping costs.  That notably is seen in the eBay treasures. I spotted a nice heathkit DX-20 for about $50 and the shipping was $65. Likely it is a twofer with part being a way to in effect charge a higher price by inflating the shipping and in part by increased shipping costs. Shipping with insurance across the US was about $150 for this jewel and that was three years ago. 6AM on the Left Coast ~ 20M Easter Sunday! My only hope is the cost of Chocolate Bunnies remains steady although a pound of See's Candies f...
Read more

August 30, 2024. A PNP 20M SSB Transceiver

Shown below is the Block Diagram for the 20M PNP SSB Transceiver steered in the  Transmit Mode . The components shown in the dotted block are relay steered so that the block module is single pass and amplifies in a single direction. The Block diagram show steered in Transmit.  Essentially the steering process works so that the IF Module input follows the Balanced Modulator on Transmit and then the input side follows the Receive Mixer on Receive. All done with some relays and a bit of RG174U coax. For those who count things in detail, this block diagram is not unlike what was used for the PSSST Transceiver which can be found on my website . Yes, a warmed over P3ST only using PNP devices. TYGNYBNT. 73's Pete N6QW
Read more