A Move to the Simpleceiver SSB Transceiver.
The Simpleceiver Plus SSB Transceiver is on the Air!
10/22/2017 ~ The Simpleceiver Plus SSB Transceiver 1st QSO with W1AW/6
It does not get any better than this -- imagine my surprise when at 9:30 AM PDST on 7.185 MHz I heard W1AW/6 calling CQ --several times. I could resist no longer. Gave him a call and the Op Marty, called me back. Boom! The Radio Gods Have Spoken. My very 1st QSO with the Simpleceiver Plus SSB Transceiver and it is with W1AW/6. This was a special events station at San Ramon, CA (SF Bay area) in connection with Pacificon (a Ham Radio Event). I was running 500 MW with the EMRFD Driver board and my report was 5X8.
Needless to say the most amazed person was me! San Ramon is about 350 Miles form the N6QW Newbury Park Laboratories. So OK -- here is a photo -- it looks like crap but works like a bomb!
The EMRFD Driver Board is at the Top Center off the bread board. I did not even have the TR relay set up so the Driver board is connected to the antenna and I was using an outboard receiver where I could switch my droopy dipole between the board and the external Rx. Today I need to get the TR relay installed and the LPF. You can see I was all set to install the LPF (The three toroids were wound just this morning and are lying just to the right of the board.)
This was an exciting day -- the Simpleceiver Pus SSB Transceiver has many innovations and what you see in the photo above is pretty much the Superhetrodyne Receiver with a few relays, a microphone amp and the driver board. Go get off the couch and heat up that soldering iron!
More Photos -- had to add a small T Type attenuator pad on the EMRFD driver stage when I discovered a RF feedback problem when it is used with an outboard linear amp. The issue was I had to lower the gain on the pre-driver to prevent the RF Feedback but that then lowered the receive gain of the stage. The Pad lets me run more gain on receive and solves the RF feedback issue.
I now have it rigged up with 2 in-line amplifiers and it will run 200 Watts output. Several additional contacts were made today at 10 watts with stations in Arizona and Nevada. Go Simpleceiver Plus SSB Transceiver! So far about a half dozen contacts today.
More Photos -- had to add a small T Type attenuator pad on the EMRFD driver stage when I discovered a RF feedback problem when it is used with an outboard linear amp. The issue was I had to lower the gain on the pre-driver to prevent the RF Feedback but that then lowered the receive gain of the stage. The Pad lets me run more gain on receive and solves the RF feedback issue.
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| The RF Amplifier board used both on Rx & Tx |
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| The IF Block that uses the relay switching for Rx and Tx |
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| The EMRFD Driver board with a 5.5 dB T Type Pad on the input [ 2X 15 Ohm and 1 X 75 Ohm] |
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| W3NQN LPF |
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| PD/BM with the single 2N3904 Microphone Amplifier
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73's
Pete N6QW
10/21/2017 ~ Addendum On the RF Stage Switching
Works flawlessly and produces 1.64 Volts Peak to Peak across a 50 Ohm load which is 6.72 Milliwatts. Next I will test the EMRFD standard driver stage (2N2222 and 2N3866) to follow this stage and see what that output looks like. It may be enough to try some QSO's. The output is clean and sounds really good. Yes I did look at the signal with my homebrew SDR receiver and Power SDR. This is exciting.
73's
Pete N6QW
10/21/2017 ~ First Look at Switching the RF Amp Stage for Rx and Tx
Here is a first look at using our J310 Dual Gate MOSFET Stage to also work as the Transmit Pre-driver stage. Again the surplus Omron G5V 5 VDC SPDT relays are doing the heavy lifting.
The above schematic is my first prototype and I will be wiring that up today. The beauty of the relay switching is that we use the inherent circuits of the Superhetrodyne receiver blocks in the Transmit stages. This means minimum building and ease of construction. Stay tuned we are inching closer to an on the air transceiver.
73's
Pete N6QW
10/20/2017 ~ Houston we have Ignition -- The Simpleceiver Plus SSB Transmitter Portion of the Transceiver is Working and Exhaling RF!
Exciting news! The Transmitter is working and for your own amusement and amazement you can see it working here. It was an exciting day at the N6QW Newbury Park Laboratories.
Some noteworthy mentions. The relay switching of the IF block module works beyond my expectations. Plenty of RF coming out of the block which now has me thinking the receiver RF amp stage could similarly be switched with two relays so that it would function on both transmit and receive. Two more blocks (low level driver stage and LPF) would yield an actual working 300- 400 MW QRP transceiver. I also found that the LSB BFO frequency seems spot on but the USB needs to be adjusted. I need to go back into the code and adjust the frequency so that the USB does not sound pinched, which you can hear on the video.
Keep in mind that by adding just a simple one transistor microphone amp and adding now 4 relays you can turn the Superhetrodyne receiver configuration into a working SSB transceiver.
In the next post I hope to get a chance to include the schematic of the microphone amp and how I wired up the RF amplifier with the two additional relays. For those who can't wait visit my website at www.n6qw.com and link on to the LM373 transceiver project and one of the linked schematics is the microphone amp.
73's
Pete N6QW
10/18/2017 ~ Troubleshooting the Simpleceiver Plus SSB Transceiver
Soon we will be having a complete transceiver and that is usually where the fun begins. No, at this point I am not addressing the fun side when you make contacts; but the agony when something isn't working and it drives you nuts. We all know that fun!
I want to share with you two stories from my earlier life that while they are not directly related to ham radio none the less tell a powerful story about when confronted with trouble shooting problems.
Taking the time machine back to 1966 I was a Lieutenant in the US Navy [For those who wonder I was USN not USNR.] Being chronically sea sick I was assigned to the US Naval Civil Engineer Corps. (SeaBees guys). In 1966 I headed a small group of principally Chief Petty Officers (most were Master Chiefs and thus at the highest enlisted rank) who each had a specialty in the construction trades. These specialties included builder, utility man, electrician etc. Our job was to assemble stateside, a complete camp that would be shipped to South Vietnam. Typically we were given a number like a 500 man camp at location X and then we would essentially assemble the parts for a "Giant Heathkit" that would be shipped to location X.
Because the Vietnam War was ramping up so quickly, we were forced to purchase COTS (Commercial Off The Shelf) products such as pre-engineered buildings. Perhaps you heard the term Butler Building which happened to be a specific manufacturer. But there were others like Strand Steel or Soule and others. These buildings were typically 40 X 100 square feet and while all manufacturers had s stock 40 X 100 foot buildings, the actual steel support structure was different and the "bents" typically were spaced differently and the anchor bolt patterns were different.
A 500 man camp may have a half dozen of these buildings. Often slabs were poured before the actual buildings arrived on site. In one of these "kits" might be buildings of several different manufacturers. Thus we got a lot of grief from the field battalions about the wrong pads for the right buildings.
A 500 man camp may have a half dozen of these buildings. Often slabs were poured before the actual buildings arrived on site. In one of these "kits" might be buildings of several different manufacturers. Thus we got a lot of grief from the field battalions about the wrong pads for the right buildings.
Back to our Master Chief Petty Officers --a unique breed all of their own. One of them came to me and said I am going to lunch, I am going to drink until I get drunk and I will solve this problem by tomorrow! He then said I assume you have no questions about what I am going to do. The next morning when I came to work there he was and he looked like hell -- obviously he had a lot to drink. Then he says about 11:00 PM the prior night he came to the office (half in the bag) and developed his solution. It was brilliant!
The solution involved creating a new universal drawing for the 40 X 100 foot concrete slabs that had embedded anchor bolts spaced apart for every pre-engineered building we used. Thus when the slab was poured extra anchor bolts were installed in the slab. When the building showed up --you simply used the magic decoder chart and cut off the anchor bolts that were not needed. About a half hours worth of work with a torch and you were ready to install any building that was delivered.
After that I frequently encouraged the Master Chief to take a long lunch hour! He was the guy who changed the Bill Of Materials to 29 common items. Initially we had four different sizes of hinges in the kits --he asked --WHY? Supply one size of hinge and it will work anywhere. We stopped supplying 4X4's and if you needed a 4X4 make it from two 2X4's This was advanced base construction not building luxury homes in Beverly Hills. The guys in the field appreciated this too as the parts shortages went way down as you only had to deal with 29 items!
We not only assembled the kits but we bought the parts --I can tell you there were over 5000 of those buildings that were bought! His solutions saved us countless man hours.
The next story took place after I had left the Navy and was working for Boeing in Everett, WA, home of the 747 manufacturing plant and the world's largest building by volume. I joined Boeing when 747 Ship #1 was going final assembly. You can't imagine the energy and excitement that filled the plant. Ship #1 typically is not sold, but is used as a flight test vehicle. As an airplane is moved down the assembly line it frequently is raised on special jacks so that access can be gained to areas that are not accessible in the normal mode.
As luck would have it as Ship #1 was nearing completion of final assembly it slipped off the jacks and one of the jacks penetrated the wing in the area of one of the fuel tanks. Disaster! Catastrophic was a common catch phrase. Most of the VP's could only think about the hit to the stock and their incentive compensation. Some of the brilliant young engineers suggested that in a month they could cut off the wing and install a new one. A month? Well finally someone said lets ask Bill Geist (he was my boss's boss).
Bill came down to the final assembly area and started laughing at what he heard being suggested. Geist ran the manufacturing line for the B-17 during WWII and planes slipping off jacks was routine. He said here is how you fix that problem --boom it was about 16 hours worth of work, which was the standard fix for a B-17 jack impalement. Once again Tribal Knowledge to the rescue.
Bill's comments were that this was Ship #1 and it would never be sold --so who cares if there is a patch on one the wings --not even visible. The program had only a slight 16 hour delay. The VP incentive stock was not hit and they even spun the story about the amazing Boeing Engineers! Bill Geist was not an engineer but sure knew how to build and fix airplanes.
Bill's comments were that this was Ship #1 and it would never be sold --so who cares if there is a patch on one the wings --not even visible. The program had only a slight 16 hour delay. The VP incentive stock was not hit and they even spun the story about the amazing Boeing Engineers! Bill Geist was not an engineer but sure knew how to build and fix airplanes.
So there is a ham radio aspect to these two stories as it applies to what we do in our hobby. Almost always there is a simple solution to trouble shooting a problem. You might have to drink a bit to find it; but don't start by ripping everything apart. Also only change one thing at a time! Spend time thinking about what could be the problem and what clues lead you to the answer. Don't raise the bridge --lower the water.
73's
Pete N6QW
10/16/2017 ~ Response to some questions.
The Ghost in the Machine has struck again and now it seems I can't respond to questions that are posted. So I will do it this way
- I used two relays for some specific reasons. One is of course thinking they would be better for the isolation issue and 2nd -- That is what was in the Junk Box. I do think this isolation is an issue as I found that was a problem when I used the diodes. The diodes did not prove as good as the two relays.
- Following on to Jan's comments. Yes a pair of TIA amps does involve six transistors just as the J310's would require 4 for a pair of amps. Jan, I guess my approach has always been that there is never a single point solution. Often I see and hear comments that the TIA is the only amp that should be used or that the Bitx is the singular approach to building a transceiver. Today I have one Bitx and only one that uses the TIA amps. Thus about 20 or so other transceivers use other approaches. The bottom line is to foster experimentation and trying new things.
73's
Pete N6QW
10/16/2017 ~ J310 Spice Model & Photo of IF Amp Block
I received an inquiry about how to find the LT Spice Model for the J310. I am not sure that LT Spice has updated the library with the J310 --keep getting a message about it being 764 days since I updated my LT Spice. Guys there is a very good reason why I don't do things like that -- I updated my Arduino IDE and none of my old sketches would work and in fact I lost some sketches. That was a disaster!
Now if you look carefully at this blog page you will see that long ago I added a Search Block. If you type in J310 Spice Model it will take you to a page about two years ago called Simpleceiver 7 and on that page is a link where you can find the spice models for many devices including the J310. [Do I have to do all of the heavy lifting? ] Anyway that page has now been updated to the following link:
So I guess it is now time for me to remove the Search Block as it obviously is not being used!
I have installed the two relays on the IF block module. I also installed a 7805 which provides power to the two relays -- tried it initially with just a 78L05 -- too much current draw with two relays. The 7805 is sitting next to one of the relays. I have yet to install the RG-174U cables which are used only on transmit but if I switch the relay --the receive signal is not in the loop-- so my quickie test tells me I wired it correctly. You can also see the board with the ADE-1 Product Detector / Balanced Modulator installed.
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| IF Block Module with Relays |
Next to the ADE-1 is a blank area for the microphone amplifier which is the next build. Once I have the Microphone Amp built I can test the low level transmit stages. See there was a method to my madness. We are getting closer to having the transceiver built. Keep in mind how I earlier said that once you have the Superhetrodyne built that you were about 65% of the way to having the transceiver --now you can see why I said that.
Stay Tuned for more excitement!
73's
Pete N6QW
10/14/2017 ~ Switching the IF Block Module ECN #2.
In an earlier series of posts I detailed how to keep the IF Amplifier Module and Crystal Filter intact and arrange for the switching of the signal direction using diode steering. My first attempt at doing that raised some issues about signal isolation and thus am changing that approach to using two simple small relays. The schematic for that change and the notes explain how it works. The relays also make it easier to retrofit the board --lots less wiring and lots less parts. The relays are SPDT from Omron G5RV - 5 Volts. They were bought surplus form All Electronics here in California. I think the price was under $1 each.
Hope you can read the drawing and the notes. Engineering Drawing was not one of my strong suits when I was in College.
We are getting much closer. I will install the 2nd relay tomorrow and take some photos so you can see.
73's
Pete N6QW
10/12/2017 ~ A Question about the J310 Configuration
Jan Ciger posted a question about why use the J310 as the basic amplifier circuit as deployed throughout the Simpleceiver Plus project, versus using the Termination Insensitive Amplifier building block from Hayward and Kopski vintage 2009. That is a good question and so I will attempt an answer as to the "why".
Fundamental to the answer is how I build things. Several days ago I responded to Johannes in downtown Freiburg suggesting he build a second receiver that was not so nicely packaged on a single board. My suggestion was that he build another one made up of modules i.e. audio amp module, RF amp, Product Detector that in effect becomes a test bed.
Thus we introduce the rationale for the concept of an Experimenter's Platform. By building in modules, it is possible to try new circuit elements without destroying the whole project. Another key factor is the use of you tube videos. You can film a baseline of performance and then when you make a change you film that as well. Boom you now have documented data like when you go to the eye doctor and are being fitted for glasses. Is lens A better than lens B?
A second point is that we started the Simpleceiver Plus Project with the concept of a very basic and universal common circuit template. The building block layout for the RF amplifier (Transmit or Receive) was essentially the same as for the Product Detector as well as the IF amplifier blocks. This made possible the use of very common parts and a limited number of parts values. The use of LT Spice enabled fine tweaking of a circuit dependent on its use. I could evaluate an RF amp circuit using the J310's and then see how that works for the IF amp. Further I could adjust the gate voltage (or introduce a signal on Gate #2 when used as a Product Detector) and see the performance change depending upon the specific application.
Now I am beginning to understand the real issue! I am not a Farhan, Hayward or Kopski! Nor am I well known in the ham community as they are. So why would I suggest the use of J310's configured as a Dual Gate MOSFET versus simply pressing on with the well documented and frequently mentioned TIA?
Obviously many homebrewer's have heard that Dual Gate MOSFETs are like ancient technology --so much so that RCA no longer makes the venerable 40673. Most DGM's made today are surface mount so another "bad feature". The TIA (Termination Insensitive Amplifier) circuit was specifically developed for use in bi-directional radio transceivers --so again why in the world would you use J310's --and who is the N6QW guy?
For your Dining and Dancing pleasure I have prepared a chart that compares some of the features and benefits of the two circuits.
In looking at the chart it depends what lens is in place ( A or B). The TIA has many fine attributes and is well known and revered in the EMRFD community. Besides the J310's have not been used in a broad band mode but rather specific use of LT Spice enabled the performance to be fine tuned for a narrow band of frequencies.
For the most part they are comparable in performance. There is one aspect that I do find as being a difference and that is the ability to use AGC or manual gain. There are several You Tube Videos where I demonstrated the manual adjustment of the stage gain in the RF and two IF Amps -- I thought that was pretty impressive!
Now for a moment back to the Experimenter's Platform. It would be an easy matter for someone with this burning question to simply substitute TIA amps for the J310 amps and decide which is better. I have built a 20 Meter transceiver using the TIA amps where initially I set the gain for the 15 dB (using the 1st set of resistors in their chart). I was underwhelmed with the performance in that there was insufficient gain and the receiver sounded deaf.
When I changed the two resistors (from the data table) in the TIA application note so that the gain was 24 dB then that was more like it. Initially I thought I had a wiring error or bad parts --nope 15 dB per stage was not enough. Keep in mind that you have 6 dB of conversion loss in a SBL-1 and there is loss in the SSB filter. By my WAG I had lost about 15-18 dB of gain in the two SBL-1's and the crystal filter. Adding about 18 dB of gain (15 to 24 = 9, and 2 X 9 =18) made it work.
I hate to say this --but it is gain across the whole topology that is the key factor --hold back the gain of the front end (because you amplify the noise as well) and make up that gain in the IF and audio stages. Thus you may get the point of my having adjustable stage gain capability for the RF and IF amps.
I hate to say this --but it is gain across the whole topology that is the key factor --hold back the gain of the front end (because you amplify the noise as well) and make up that gain in the IF and audio stages. Thus you may get the point of my having adjustable stage gain capability for the RF and IF amps.
While I have not measured any noise figure ( I don't think I would even know how to do that) but I can tell you and others have commented --the signals seem to "pop" out of nowhere and the background noise between stations is low. So I guess that counts for something.
For those who may not believe N6QW actually built a transceiver using the TIA amps see below. [So OK stop drooling --- it does look like a rather nice layout!]
Now Jan, back to your question. You need only to listen to the current You Tube videos and ask do the J310's configured as a DGM sound OK? After all it is how it works and not so much what is under the hood.
Maybe a more fundamental question would be would I ever use a TIA circuit again? The answer is it depends but more than likely not. My first choice would be the J310's followed by the Bidirectional circuit I developed using the Tri-Quint MMIC amplifiers. The Blue Rig at the top of the masthead has the MMIC amplifiers for one of the stages. Given what is the Simpleceiver Plus project (a clue is in the name), the J310's were a clear choice.
Maybe a more fundamental question would be would I ever use a TIA circuit again? The answer is it depends but more than likely not. My first choice would be the J310's followed by the Bidirectional circuit I developed using the Tri-Quint MMIC amplifiers. The Blue Rig at the top of the masthead has the MMIC amplifiers for one of the stages. Given what is the Simpleceiver Plus project (a clue is in the name), the J310's were a clear choice.
Thank you Jan, for your question as I am sure others would want to know why I did what I did.
73's
Pete N6QW
10/11/2017
It is always best to start with a block diagram and this is shown below. You will note the blocks that are highlighted in yellow which reflect what is built so far. Noteworthy much of the built receiver becomes the transceiver.
I have posted several videos of the Simpleceiver Plus receiver configuration and I believe what you heard reflects the performance built into the design. Now look carefully at the block diagram you will see that many of the circuits are used both on transmit and receive. So this should be a huge flashing billboard that by working on the receiver and having it perform well will carry over to the transmit side as they are the same circuits.
What is not shown is the control/switching circuitry which will be detailed in subsequent postings. Thus it is imperative that you have the receiver working just as you heard on the you tube videos before starting the transceiver.
The next few days I will spend cleaning up the Simpleceiver Plus bread board by removing the original Product Detector and installing the ADE-1 onto the bread board. the plan is to take detailed photos so you can follow along with your build. We are getting closer.
73's
Pete N6QW