An Old but Cool DiFX: The Epiphyte

I've been hearing about this rig for many years.   It first appeared in the September 1994 issue of QRPp, the journal of the NORCAL QRP club. A condensed version of that article appeared in SPRAT 81 (Winter 94-95). The designer is Derry Spittle VE7QK from Vancouver, British Columbia.

The name always puzzled me.  Here is the explanation:  It started with the Neophyte: A very simple direct conversion receiver that many of us built.  The Neophyte was mostly an NE602 and an LM386.  In the Epiphyte, a crystal filter and a second NE602 were added, turning the Neophytes into a superhet receiver and -- with some additional circuitry -- an SSB transceiver.  The Oxford English Dictionary reportedly defines an Epiphyte as "a plant that grows on another plant"(see picture below).   The Epiphyte grew out of the Neophyte.

And this plant grew in British Columbia, which seems -- like Australia and New Zealand -- to be fertile ground for simple phone rigs.  I'm pretty sure the "Wee Willy" DSB rig also came out of BC, and it may have had a similar purpose:   allowing for portable contact with the BC Public Service Net on 75 Meters.  

There are many features of the Epiphyte that I like:  There is a simple 455 kHz filter and a ceramic resonator BFO/Carrier oscillator. The original design featured a VXO-like circuit using a ceramic resonator at 4.19 MHz.  And it ran off AA batteries (as did the NE602 DSB rig I took to the Dominican Republic).

Unlike my NE602 rig, the Epiphyte made an artful use of the fact that NE602's can be set up to have TWO inputs and TWO outputs.  Where I used DPDT relays to switch inputs and outputs from both NE602s,  OM Spittle left all the inputs and outputs connected, and simply switched the VFO and BFO signals.  Ingenious.  

There were updates and improvements.  The Epiphyte 2 and 3 featured increased power out (5 watts vs. 1 Watt).  Version 3 has an IRF-510 in the final, driven by a CA3020A chip.  That chip is capable of 70 db gain.  Wow. 

In 1996 NORCAL and G-QRP donated 50 EP-2 kits to radio amateurs in third world countries. Very nice.

In 2000 NORCAL did a kit of the EP-3 -- it sold out in 24 hours.  Here is a nice article on the EP-3:
http://www.norcalqrp.org/files/Epiphyte3Mnl.pdf

And above we have a video from Japan of an EP-3 in action.

It's Ugly, But It Gets You There: Pete's Latest Rig

That, my friends is an extreme  example of what we mean when we use the word "rig." This magnificent machine sent Pete's melodious voice across the mighty Pacific several times during the recent CQ WW contest. 

Pete wrote to Jun:

Hi Jun,

 

This weekend is the CQ World Wide SSB contest and I just worked three JA stations on 40 Meters. The time 1400 UTC. I must confess that I was using 600 watts to my droopy dipole but they came back on the first call. So there are paths open and perhaps 600 watts was overkill but the timing seems like it works for a good path to the west coast. Along the way I also worked a station in Hawaii (KH6).

 

See if you can find some 813 tubes as they make a great grounded grid linear amplifier tube and a pair will give you 600 watts. see http://www.ohio.edu/people/postr/bapix/813amp.htm

http://ham.homelinux.org/schemi-pdf/59hb199.pdf

 

The rig I was using is shown below. The mainboard came from a Hallicrafters FPM 300 (late 1960) to which I added the Rx Tx Mixer (SBL-1), my stock 2N3904 bi-directional amp board, the 2N2222 + BD139 driver stage using the EMRFD circuit and a 2SC2075 final which gives about 3 watts. This in turn drives an intermediate SS amp to 100 watts and then the SB200 to 600 watts. The FPM 300 used a 9.0 MHz IF frequency.

 

Of course no rig today from N6QW would  be complete without a Si5351 and the color TFT display. Rounding this out is an LM386 audio amp stage. Cosmetically the rig doesn’t look pretty but sure works well.

 

73’s

Pete N6QW

(The comments about the 813s are kind of SHOCKING, coming from a member of the QRP Hall of Fame!)

JH8SST/7's Build of Pete's Simpleceiver

Beautiful. 

Makes me want to put S-meters in my rigs.

More on Pete's design here:

http://n6qw.blogspot.com/2015/09/simpleceiver-40m-ssbcw-receiver-and.html

Ryuu's Receiver (Superhet using Si5351 and Color Display with IF at 10.7 MHz from JA2NKD)

The influence of Pete Juliano is spreading far and wide.  Those little color screens attached to Si5351s seem especially popular in Japan.  Above is the receiver of Ryuu JA2NKD.  Below is the schematic.  Click on it for a better look, or use this link:
http://ja2nkd.c.blog.so-net.ne.jp/_images/blog/_206/JA2NKD/7MHzcolorLCDSchematics.jpg?c=a1

Ryuu's blogs are here : http://ja2nkd.blog.so-net.ne.jp/
and here: http://ja2nkd.blogspot.jp/
They are in Japanese.  Google Chrome does a poor job at translating them, but you can get the gist.  In any case the pictures are great and the schematics are understandable by all of us.  Thanks Ryuu!

JH8SST Build's Pete's Simpleceiver (video)

Jun JH8SST made this nice video about his version of Pete Juliano's Simpleceiver.   I like the approach of putting the stages on separate boards, but perhaps Jun could have made things easier by using Manhattan-style construction on those boards.  And of course I like the breadboard-style aluminum sheet.  FB Jun.  

Jun writes:

I've built a simpleceiver, which is a modified version.   My first main board didn't work because of several problems, and that's why I decided to divide the board into several separated PCB's with some circuit modifications.

 

RF and Mixer stages are original, but I employed an 8pole 9MHz ladder Xtal filter.   The J310 X 2 is used in IF amplifiers, but load resonant circuit is modified to use a type 10K coil form and a ceramic capacitor.

J310 product detector is original and built on a tiny PCB, as shown in attached photo and YouTube Video.

 

This modified Simpleceiver has high sensitivity and more than enough gain. I needed to reduce RF/IF gain to eliminate product detector distortion caused by stronger signals.

 

This simpleceiver works really nicely.

 

I'm going to re-modify it to make it as original as possible.

 

The block diagram is:  J310X2 RF－DBM－9MHz 8 pole X'tal Filter－J310X2 IF－J310X2 IF－J310 product detector－AF　μA741－AF LM380 with NFB.

 

I'm going to re-modify it as:  J310X2 RF－DBM－J310X2 IF－12MHz 4 pole X'tal Filter－J310X2 IF－J310 product detector－AF　μA741－AF LM380 with NFB.

 

I'm also going to add an AGC system using a modified W1FB AGC circuit.

 

1625 Tubes and Si5351 Chips: JH8SST's FB Rig

Peter has been helping Jun JH8SST and other Japanese hams get their Si5351 synthesizers working with various displays.   Jun has had some great success as you can see in the above video.  I really like the combination of old (1625) and new (Si5351) technology.

Jun is a long-time homebrewer who as built some amazing stuff.  Check out the pictures on his QRZ.com page:

http://qrz.com/db/JH8SST

And look at his cool 128x128 TFT display:

Other videos here:

https://www.youtube.com/channel/UCcY94imiTswpjPcfcUIbNcg

From Vietnam to Washington DC -- Jonathan-san KC7FYS W0XO 7J1AWL XV2OC Stops By With His AT3b

I first saw that QRP Altoid-tin ATS-3b rig  around 8 years ago in pictures that Jonathan-san sent from a beach in Vietnam.  He and his family were there on vacation from Japan.  (Included was a memorable picture of his young son in an NVA helmet.) During this time period Jonathan also tried (unsuccessfully, I'm afraid) to teach me how to properly pronounce the name of that famous electronics market in Japan.  

Jonathan and his family were in Washington yesterday and we got together for lunch.   It was great to finally meet them.  And to see that well-travelled ATS-3b.

Jonathan is a big fan of the ATS-3b, and for good reason.  A very neat rig.

Plug in filters for the ATS-3b.

The meaning of "CM" in the Toyo CM-455 Filter

Photo by ZS1KE

A while back I picked up (from e-bay?) a 455 kc crystal filter for use in my Lew McCoy "Mate for the Mighty Midget" receiver.  I did a quick and dirty installation.  It kind of worked, but I had it in the back of my mind that I had to work on the impedance matching to ensure minimum passband ripple.  But when I learned what the P, B, E, and G pinout designations meant (plate, B+, earth and grid), I realized that this device had been designed with tube impedances in mind, so I probably didn't have to mess around with input and output networks (as I've done with the BITX rigs).  Last week I installed it as the manufacturer intended -- it sounds great.

Today I started wondering about the passband characteristics of the device.  What do the skirts look like?  So I started Googling.  There is not much out there, but I did come across a really interesting Epson site that describes the origins of this filter, and what the CM means.  CM is for "Crystal Mechanical."   Wow, this little box combines the characteristics of  a crystal filter AND a Collins Mechanical filter:

http://www5.epsondevice.com/en/information/technical_info/qmems/story2_5.html

An excerpt:  

"While at the Electrical Communication Laboratory of NTTPC, Mr. Nakazawa had had a flash of inspiration: ‘We could develop a crystal unit with a high Q factor by using the wire mount technology I'm studying now. Then, if we can achieve the idea of a mechanical filter that mechanically joins multiple units using quartz material, we should be able to develop a compact filter that achieves both excellent filter characteristics and thermal characteristics.’ Without a pause, he quickly tackled the next development issue, which resulted in the creation of the ‘crystal mechanical filter (‘CM filter’)*5). This CM filter was manufactured by processing the quartz substrate into an ‘H’-shaped filter element and functioned by using the long thin sections on the left and right sides as resonators (Figure 1). The middle portion connecting the two sides fulfilled the role of the coupler. This was precisely the ‘mechanical filter achieved using crystal (quartz)’ that Mr. Nakazawa had envisioned.

This filter was released on the market as a 455kHz intermediate frequency (IF) filter for single-sideband (SSB) modulation in radio communications. The use of quartz material meant that not only were good filter characteristics achieved, but thermal characteristics were also excellent. As this was the first filter to offer properties of this caliber, it sold extremely well throughout the world. Furthermore, this technology received the honor of being granted the Notable Invention Award from the Science and Technology Agency."

Does anyone have the specs on these filters, and perhaps a passband graph?

Three cheers for Mr. Nakazawa!

Kids Homebrewing in Japan in the 1920s

 

Michael Rainey, AA1TJ, Poet Laureate of QRP and Wizard of the Vermont Hobbit Hole found this drawing and put it on his face book page.  It is clearly supportive of the "International Brotherhood of Electronic Wizards" theme of this blog, so I have shamelessly expropriated it.  All for the cause Michael!   I hope this indicates that OM AA1TJ is emerging from a too-long spate of radio-inactivity. 

 

Michael says the drawing is from the 1920's children’s magazine, "Kodomo No Kuni" by Kiichi Okamoto.  David Cowhig, WA1LBP, provides this translation:

 

Title "Ni-chan,  I can hear it!"

The radio kid is saying something like:

-- Wait, no I lost it.

-- uhhhh

-- I can hear it, I can hear it, I've got it!

 

David notes: Sometimes Japanese use the katakana syllabary to add emphasis like we might with italics or exclamation points. 

 

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Been There, Done That: "...he begged his oscillator to osc and his amplifiers to amp."

This ad is from the December 1931 issue of QST.   This copy has a LOT of mileage on it.   In 1993 or 1994, David Cowhig (now WA1LBP) was living in Okinawa Japan and was operating as 7J6CBQ.   I was living in the Dominican Republic and operating as N2CQR/HI8.   We were both contributing to a 73 magazine column (as "Hambassadors"!) and we were both in the Foreign Service.   I wrote to David -- he wrote back, sending me some old QSTs, including the one from which the above ad is taken.

This ad shows that many of the homebrew/troubleshooting woes that we face today are very old.  And that having access to good technical books is very important when you are trying to overcome these difficulties.  

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Back with the Sats: Catching Cubes with a Dongle

I've been playing around with a little $13 DVB-T SDR Dongle receiver.  These devices normally tune 24 MHz to 1.7 GHz, but I modified the first one I had so that it would tune the HF bands.   Pete then sent me another one, which I vowed to keep unmodified, thinking that it would be fun to use it to listen to the many small Cube-Sats that are up there.  Most have downlinks (and Morse Code beacons) in the 470 MHz range.   I whipped together a simple ground-plane antenna for this band (One 6 inch copper wire as the receive element with 4 five inch groundplane elements). 

 

I then went to the "Heavens Above" website, plugged in my location, and clicked on "Amateur satellites."  This gave me a very accurate schedule of satellite passes.  I started listening. 





First I heard (and saw in the HDSDR waterfall)  the CW beacon of the Prism satellite at 7:05 am EDT today.  Prism is from the University of Tokyo and was launched from Japan.

Then Cubesat XI-V at 0711 EDT.

Cubesat XI-IV was heard at 0813 EDT.  The Cubesats are from Japan and were launched from Russia.  

ITUsPAT was heard at 1422 EDT.  The I is for "Istanbul"

Finally,  I monitored a pass of the Japanese FO-29 satellite aka JAS-2 at 1611.  Wow, this was like old times on the RS-10 and RS-12 satellites.   Lots of CW and SSB stations in the downlink passband.   Lots of fun.

At 470 MHz the Doppler shift of a low-earth orbit satellite is quite noticeable, and helps confirm that you are in fact receiving sigs from an orbiting device.

I thought it was pretty cool to take a $13 DVB-T Dongle, connect it to a small, copper-wire antenna, and use it all to receive signals from some 4"x4"x4" cubes in orbit of the Earth.

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A Different Kind of Workshop

Sometimes it is good to take a break from the electronics and look at how people are making other things.  I've been working on the heat sink for a 140 watt solid state amplifier, so this fellow's comments about working with metal kind of resonated with me.   


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BITX 5 Watter Makes the Trip to Tokyo

The solar flux index was only 151 this morning, but grey line conditions to Japan were very good.  Yoshi, JA1OJJ, was booming in on 17 meters.   We had a nice chat.  He said I was 55.  His 5 element quad helped a lot!   

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DSB Transceiver with Only 3 Transistors

Wow.  Looks like something Peter Parker would really like.  This one was sent to me by Stephen, G7VFY.  It comes from Japan:
http://www.cqpub.co.jp/hanbai/books/15/15061/15061_p.180-181.pdf

From this book:-

http://www.cqpub.co.jp/hanbai/books/15/15061.htm

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Santa Arrives at SolderSmoke HQ! Rigol and Black&Decker

Santa Claus obviously heard my distress call when the TEK 465 gave up the ghost.  This morning it was replaced by a RIGOL digital scope.   I'm going through the tutorials.  Wow, lots of features.  A Black&Decker jig saw also arrived -- this will help in my cabinetry efforts. 

Last night just before dinner I talked to Kiyo, JH1MDJ, in Tokyo on 17 meter SSB with the 5 watt BITX.   I kind of broke through a small pile-up and we then had one of those "please repeat your power level... I can't believe that is 5 watts to a dipole" conversations.  

Happy Holidays to all!

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Now That's A Radio Shack! JH0JDV

I was at the workbench this morning, working on a 30 meter DC/DSB transceiver.  I had the Barebones superhet tuned to white noise on 17 meters.  Then I heard a strong CQ that sounded like DX.  It was Ely, JH0JDV.   He was the only signal on the band.  We had a very nice contact, no problems at all.  I was running my normal 10 watts to a dipole.  Afterwards I Googled him.  Wow, he has a REAL radio shack!  FB Ely!

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FITSAT-1 Flashing Morse With LEDs from Orbit

Very cool:  Japanese students sent up a small satellite.  One of its capabilities is to flash Morse code messages in the visible light range using LEDs.   Prepare to peg your geek meter: 
http://www.fit.ac.jp/~tanaka/fitsat.shtml 

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Homebrew Hero: Kazuhiro Sunamura, JF1OZL

In case anyone in the SolderSmoke community has not yet visited the site of Kazuhiro Sunamura... Be sure to check out his site. He has a really amazing range of projects:

http://www.intio.or.jp/jf10zl/

Here is the bio of OM OZL. As you can see, he definitely has the Knack, and clearly has the sharing attitude of a true member of the International Brotherhood of Electronic Wizards:

My name is Kazuhiro Sunamura. I am a 50 year old mechanical engineer, born in 1956. I am not an engineer in electronics. I have been interested in electricity and radio from the age of ten. For the last ten years, I have been active on my ham radio station JF10ZL. I have also written articles about my some of my radio projects in Japanese for the Japanese CQ Magazine. Now I have decided to get onto the internet and will take the opportunity of showing you my equipment and ideas. Please have a look at my schematics. I will be very happy if this material helps you with your own radio projects. I am a member of the J.A.R.L. affiliated Tsuchiura Club, the local ham club in my home town.

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