Techie Stuff!

So, if you are a contester or just plain operate only, time to zone out because today I want to cover a steerable 4.9152 MHz IF module. So, this post translates to Techie Talk. 

Bored? As an alternative you could try to locate the Ham Radio Chick's You Tube channel, where she will update you on her latest POTA adventures following her 8-day sprint to an Extra Class License.

The reason for covering this module again is because in less than 10 square inches you have a powerful piece of technology to wit:

Transmit and Receive mixer (SBL-1)

1st IF AMP using J310's as a DGM

Homebrew 4.9152 MHz 4 Pole Crystal Filter

2nd IF Amp using J310's as a DGM

Product Detector/Balance Modulator (ADE-1)

Audio Filter on the Out/In of the PD/BM

Ride along 4.9152 MHz BFO

The DGM Amps have trim pots to balance the input and output signals to achieve low distortion and good signal and noise handling.

The 1st IF Amp is a Tuned Amp and the 2nd IF Amp is broad band (No this is not Ina Rae Hutton's all girl band). The signal path through the 1st and 2nd IF Amps is always in the same direction and two small on-board relays steer the IF Module input to either the SBL-1 or ADE-1 depending on whether in Receive or Transmit. (Something 1st seen in the EAQRP Club "Pilgrim" radio.)

This was an earlier You Tube Video of this rig. Yes, it had some warts, but the plan is to fix those hiccups. That is a fun aspect of the hobby for me. 

Yes, there are few I can hardly hear you, but you are 5X9 comments to be heard while you build stuff. So, if you need an hourly dose of 5X9 Park 160079... that does happen during rig fabrication.

Also needed for a complete rig is a digital LO, a display, a steerable (Rx and Tx) RF Amp, a Band Pass Filter. Low Pass Filter and TR. Not mentioned as yet the Transmit Driver and Final Amp.

Them that know, now don't care if you know.

73's

Pete N6QW

The Weird, the Strange, the Arcane

A Tri-Band "Hot Water" SSB Transceiver

Back in the day when hams were more than appliance operators and delved into the circuitry of many of the radio models, they always were looking for an opportunity to upgrade their radios.

Heathkit struck gold when they produced the Mono band SSB radios. The individual kits cost about $100. Often hams would want additional bands and thus Heathkit sold more product. 

But enter the ham entrepreneurs who found ways to modify a Heathkit mono band unit to add more bands. I do know there were commercial kits sold to do this on a limited run basis. The above photo shows a tri-band Hot Water. This is an eBay listing, and I am uncertain if this is one of the modifications kits or the radio was modified similar to the kit.

I see the potential of ripping out the VFO and installing a ESP32 and Si5351. Maybe even the JF3HZB circular dial. 

Lots of possible improvements/modifications using the low-cost technology sold at Bozos. (BoJack + Bezos).

The Fox Hole Radio Set

It doesn't get any simpler... a rusty razor blade (iron oxide) a safety pin, a coil, some antenna wire and a set of headphones. This was a staple of many WWII "ground pounders" as it requires no electricity, something to fit in your 782 Gear (USMC term for a knapsack) and could be something that provided entertainment. 

For those who wonder the term 782 Gear comes from the USMC and the 782 refers to the form (form number) each "grunt" must fill out to validate that he or she received a knapsack and if you lose it, the form is evidence at a court martial. The Marines assure accountability. Thus, the form number became the name for the equipment.

The Rusty Razor Blade is a cousin to our galena (iron pyrites) crystal detector.

Cognitive Decline is real and is readily visible.

Them that know, now don't care if you know.

73's

Pete N6QW

Ugly Weekender

When I first heard the term Ugly Weekender, I thought of the young ham guy who went out partying Friday night and through an unfortunate incident of beer goggling* awakes the next morning to see a YL like this next to him. That had the makings of a true Ugly Weekender.

*Beer Goggling

C'mon guys it's somebody's Grandma!

We are not covering that kind of weekender but one that highlights that seminal W7ZOI project involving a CW transceiver. The Ugly Weekender was mentioned in yesterday's blog and the link has a you tube video.

Ugly Weekender

There is an elegance to the W7ZOI design in that it is a Direct Conversion Receiver with a tunable analog LO and that LO serves as the frequency source for the Transmitter.

For those ashamed of being an Amateur Extra and don't own a soldering iron or have never built anything, this is a project for you. 

The reason I suggest that is that you can build the receiver first and listen to how good a DCR can sound and then you can add the transmit side. 

Now there are many DCR receiver projects including mine or the N2CQR/KK4DAS effort and certainly both will serve you well. BUT building the W7ZOI version inextricably connects you to the great W7ZOI.

The Ugly Weekender (UW) involves no beer goggling and is a sparse design meaning you can do it cheaply. The UW also affords an opportunity to eventually rip out the Analog VFO (get it working with what is designed first) and then add a Nano and Si5351. 

Thus, the UW is a steppingstone project that builds ones CV (Curriculum Vitae) by bridging the Analog world with the Digital world.

It is a project like this from the father son team (Wes and Roger) that embodies the true ham radio hobby. Keep in mind before you can contest or operate... somebody had to design, build and test a radio.

A cute definition I heard regarding the term "cognitive decline" which is where an older person pisses his pants, doesn't care, blames others and covers over the spot with make-up. There are some clever people out there working overtime.

Them that know, now don't care if you know.

73's

Pete N6QW

Implementing a W7ZOI Design

Anyone who has been a licensed ham longer than 45 Minutes knows Wes Hayward, W7ZOI.

If you have SSDRA (the better) or EMRFD (the lesser) or built a Direct Conversion Receiver or a Crystal Filter or a TIA amp or the Competition Grade CW Transceiver or the Ugly Weekender... That is the handiwork of Wes W7ZOI.

In December 1989 and January 1990, Wes had a two-part article in QST which documented a 20M, QRP Solid State, SSB/CW Transceiver. Quite a feat at that time or any time. This project was beyond minimalist as fully built out it had multiple Crystal Filters. It actually was a trans-receiver which shared a common LO and BFO, thus separate filters in the receiver and transmitter. 

A link to the 2-part article

I could not resist replicating W7ZOI's project save for the hinky way he did CW and the Analog VFO sans VFO Stabilizer. It was a challenge I took on.

My implementation added Break-In CW and the use of the EI9GQ PIC based (16F84) VFO stabilizer. Most of the rest of W7ZOI's design remained intact with the exception of the IF stage/AGC which was a suggested change from W7ZOI. My only contribution was the break in keying and the addition of the Digital Display and VFO Stabilizer from Ed, EI9GQ

I had been in contact with Wes, and he said maybe you would like to try this IF as it uses 3N209's which he sent me as well. He asked if I tried it to give him feedback on how it worked.

The Revised IF Amp from W7ZOI. Empty Sockets = AGC

Replacement AGC

Ferrite Beads on the Gates

A View of the Innards

Essentially, I was Beta testing what would eventually become the HYCAS IF. The AGC seemed to hang up for me, and I Installed a different board. When all done, I shared my results with Wes. As those who homebrew know the final HYCAS did not use the 3N209's.

The XF-9B is an 8 Pole, 9 MHz Crystal Filter from KVG in Germany. OT homebrewers know this was once the ne plus ultra of Crystal filters. So, the newly minted 45 Minute Extra asks where is that filter in my IC7300. Didn't the test answer guide cheat sheet explain about different SSB generation technologies?

My build ended up with a big and heavy homebrew box. Yesterday afternoon I worked an HI7 station in the DR. 

My receiver uses the 8 Pole KVG Crystal Filter and the transmitter a 6 Pole from the G-QRP Club Sales. The receiver design is by far one of the best I have seen. 

This project required an advanced amateur to fabricate and not for someone who knows nothing about electronics.

Note: No Manhattan or Ugly construction here.

News Flash: Bozos selling the Baofeng UV5R for $16. Such a deal Vinny!

Them that know, now don't care if you know.

73's

Pete N6QW

The B and B of Ham Radio

No, we are not talking about some cutesy cottage with great food in a corner of New England (or maybe even Connecticut) but the B and B of Ham Radio.

Finally, you guessed it: a Bitx4o and the Baofeng UV35. I suspect the newly minted Extras may have had to struggle with the B&B since those are not rigs on the memorization list.

Up front I own one of each. The Bitx40 you see in the photo is no ordinary unit as it was gifted to me from friend N2CQR as a Tech Special. Bill often receives units like this (broken) and will occasionally pass some on to me. I think he does this with a twinkle in his eye... a chance to drive me nuts chasing down problem rigs.

I say this is a special Bitx40 as I figured out how to add USB to an otherwise LSB only radio. Of course, USB on 40M has only one use and that is FT-8 (or to talk to the group that only uses USB on 40M).  The solution was not to supplant the BFO crystal with one of the opposite sideband frequencies but instead change the LO frequency.

The Bitx40 as stock used a High IF Frequency (12 MHz) and a low LO Frequency (5 MHz) and with the BFO chosen this results in LSB.  Now if we place the LO above the IF Frequency (19 MHz) and subtract the IF from the LO, we get USB. So, a single BFO frequency will give both LSB and USB.

A second Bitx40 Tech Special from N2CQR was converted to 17M. I had to change out the BPF and LPF and create a digital LO at 30 MHz (30 -18 =12).

The other huge hill climb was the Digital LO as this leverages the excellent Bitx topology into a highly functional, stay on frequency, dual mode (USB/LSB) POTA capable radio.

I sure hope the BTE's were awake during this techie talk.

The plastic case for this Bitx was originally intended for first aid supplies and was waterproof. Time deteriorated the plastic and so it was a good idea gone bad.

The next B in the B&B duo is my Baofeng UV35.

N6QW's UV35

This Baofeng UV35 was acquired 13 years ago when I moved back to California. As luck would have it I have a ham friend who lives 500 feet from my QTH. When I 1st moved here, I spotted his antenna and you know the deal. Upon our 1st meeting he showed me his Baofeng which I think could be bought with some accessories for about $25 at Bozos. I bought one right away.

Then I heard stories it might not be legal with spectral purity. But it had some other features like a flashing light, a siren and FM radio. For a while I took it walking with me and used the FM radio to listen to NPR. I think I made one contact with the radio, and my report was scratchy and not full quieting. Now when I walk, I just use my smart phone and either listen to my stored music or internet radio.

So with 1/2 the total US ham population being Technician class likely lots of Baofeng's are on the air and they now might be legal and good for 10 watts.

Them that know, now don't care if you know.

Some people in high government offices seem to be thrown under the bus as that is in vogue today. Reminds me of the Circus Maximus and the throwing of people to the hungry lions.

73's

Pete N6QW

Where to find...

Where to find Nemo? I have no answer! And whether the head of DHS will be sacked or impeached. Same answer! 

But if you want to build my MC1496 based Direct Conversion Receiver

or the upscale 1496 SSB transceiver... then where to get quality MC1496 IC's. The answer is Jameco Electronics for the leaded version, and the single unit price is $1.95. Mouser sells an SMD unit for $0.35.

Funny how about 15 years ago I bought the same leaded IC from Jameco for $0.69 unit cost. I think I splurged and bought 20 for less than $15.

Jameco also has the hard-to-find miniature ceramic trimmers we all love to use in homebrew band pass filters.

Where to find Accountability

The blame game is ongoing in our Nation's Capital. It will take on the proportions of the biblical times where St. Peter thrice declared I do not know this man. I guess it is easier to deny things once you move up the chain of command.

This reminds me of an incident at Chu Lai, in 1965.  I had the OOD watch and about midnight we received what we thought was a probe in our defenses. 

Standard protocol: I took a squad of men along with myself and we proceeded to investigate. At that time there was a certain looseness in what kind of arms you carried and while I had a 45, that day I wished I had a .45 caliber Grease Gun. The Marines had M-16's and the Seabees M-14's. (The reason I wished I had a Grease Gun.)

We had with us this interesting tool called a rocket flare. It was about 18 inches long and 1 inch in diameter. The cap was removed and placed on the base and essentially was a firing pin to fire a 22 cartridge which ignited the flare. The initiation process is where; you pointed it upwards and slapped the base with the palm of your hand. Our flares were armed as we searched the area of possible penetration.

Things were going smoothly as we inched along in the pitch-black night when all of a sudden, I saw a flare going horizontal and it hit our point man on the side of his face. I immediately shouted the command "hit the deck" awaiting enemy gun fire. 

Two of the Seabees closest to the point man doused out the fire as we were all lit up. Luckily there was no follow-on firing from the Viet Cong. We carried the injured man back to sick bay and immediately we were all interviewed as to what happened.

There were 12 of us and minus the severely injured man there were 11 different statements of observations. No two matched. 

Finally, the real truth. One of the squad members with size 14 shoes admitted that he tripped. He had an armed flare in his right hand as he fell the flare hit the ground first and its trajectory was more horizontal and thus hit the point man. The Board of Inquiry ruled it as an accident attributable to the fog of war. 

The purpose in sharing this story is that likely we will never fully know what happened in Minnesota, as the prevailing winds blow in the direction of obfuscation with zero accountability. Come the Mid-Terms we all get to send our message of accountability. 

Them that know, now don't care if you know.

73's

Pete N6QW

More Homebrew Radios From N6QW.

For those who astutely follow this blog you have likely noted that I have only built radios in the HF spectrum. Even then it has been typically 75-15 Meters. In an attempt to build a 10M radio, that got sidetracked when the XYL's (SK) health issues got significantly worse. 

The two radios we are covering today are directly related and in fact the smaller of the two was an attempt to shrink down the first version. In 2011 I was on a quest to build a shirt pocket sized SSB transceiver. The 1st version you would need a very large pocket (2X3X5) and the second version was 2X2X4... closer to pocket size. So, referring to an earlier blog posting these two are the exact same radios only one was shoehorned into a smaller topology.

1st Version of the Shirt Pocket SSB Transceiver

The band of choice was 20M and both rigs had a crystal switched VXO to give about 100 kHz on the active part of 20M.

Version 1 after the disaster.

Jointly they were the subject of an article in QRP Quarterly. [For those who want the circuit details check the Summer 2011 Issue.] The 1st version was in a maintenance mode and as luck would have it the screwdriver I was poking around with shorted a DC rail and a mushroom cloud appeared over the bench. Many of the circuits were fried and a rebuild netted a radio that actually worked better (Digital LO) and was larger (not prone to shorts). That event occurred about 5 years ago.

The smaller version got small because I left out some features and a 2X2 panel was the smallest size I could get and still have the I/O functionality. One of the things left out was the Rx RF Amp which caused V2 to be anemic on receive. That one too had the same VXO. A couple of years ago I rebuilt Version 2 to incorporate a RF Amp and a Digital LO with a super slick scaled down color TFT. Its size went from 16 cubic inches to 24 cubic inches.

Small PCB with red and white wires is the added SMD RF Amp Board

Just another day in the Shack for an old Extra Class Ham and these radios both have homebrew crystal filters at 4.9152 MHz with an LO in the 19MHz range. I always wonder if a BTE could pull off a rig like this. 

Them that know, now don't care if you know.

Questions to ponder. Has the DHS head been thrown under the bus or is it just another day at the WH? Is it a case where no one in the current administration is a rogue actor but typically are just following the script.

73's

Pete N6QW