The Cub Lives!!!!!! (For Real, This Time)

 Yep, you read it right, the transceiver that I gave up on months and months ago sprang to life. I had a feeling that it wasn't dead, my heart of hearts told me that. 

So, what happened, and what did I learn? Here's the important thing: There's more than one way to do something. Ben Franklin once said, "I didn't fail the test, I just found 100 ways of doing it wrong," and that's what I did. 

With the help of various QRZ.com members, namely KL7KN, I figured out that the receiver can be adjusted with the probing of U2's Pin 1. U2 is an SA602 and is the filter mixer. Probing Pin 1 bypasses the filter circuit, which in essence creates another antenna. The antenna will generate a buzzing or hissing noise. From here, tune L1 and L2 for maximum noise. If you can't hear any stations when you bypass the filter, you still have a problem, unfortunately (once again, thanks A LOT KL7KN!).

I can't tell you how much joy I felt when I began to hear stations when I connected an antenna. It really made me happy when I could hear the FT8 frequency, which means that my tuning was dead on where I wanted it. I could also hear CW stations with ease.

By now, many of you are wondering how well this stacks up to the Pixie. I will tell you that it blows it out of the water completely. The Cub has a crystal filter, an onboard audio amplifier, a great tuning range, and about 2W of output power that can be varied if you want to work QRPp. While the Cub sounds impressive, there are some drawbacks to it. It needs to warm up for a couple of minutes before you transmit so the frequency is rock solid. I also found the alignment to be a bit cumbersome, but that may be because I haven't built a kit like this before. While the audio is acceptable, I feel that it could be a bit louder, but it definitely beats the Pixie's quiet and wide-open receiver any day. For the completed project, I took some photos.

I set the Cub aside and waited to touch up the transmitter side of things until the next day. Turns out, the transmitter side of things was not as complicated as I had thought. In a matter of under 30 minutes, I had a fully-functional Cub, with 1.5 watts of output on 20m. 

In addition to this, I built my own 50 ohm dummy load with a wattmeter output. That can be found here: https://www.qsl.net/kc6wdk/QRP/wattmeter.htm. Here is what mine looks like. I do want to note that my copper chloride etchant, used with a nail polish resist, works very well.

To close, this has been an exciting and fun adventure. Now I'm off to build a dipole antenna and perfect my Morse Code! My next test with this is to see if I can show up on the Reverse Beacon Network, or RBN. 

If you also want to use the RBN, it's easy! Just send the following in Morse Code:

CQ RBN CQ RBN DE [callsign] [callsign] K

CQ TEST CQ TEST CQ TEST DE [callsign] [callsign] [callsign] K

The RBN looks for CQ calls, so even if you just send out CQ, there is a good chance that you'll show up on the RBN. There are thousands of operators listening on thousands of frequencies and reporting daily. If you know how to send CQ and your callsign in Morse, you'll have no problem showing up on the RBN. It is popular with QRPers in particular since QRP can be a little unpredictable as to where you will reach. Having your callsign show up on the RBN site can give you a generalization of where you can be heard and what you can work.

That's all for now from my shack. Hope you have a great New Year! Until next time...

EDIT 1/2/2023 - Just a few moments ago, I sent out a quick CQ call on the Cub using my EFHW. As soon as I finished sending my callsign, I got a report from the East coast at a distance of 963 miles, which equates to around 647 miles per watt! Not bad, especially for 1.5 watts and a crappy end-fed antenna. I'm off to build my dipole now and brush up on my Morse skills...

Updates on the Cub's Conditon/Hammo Can Completion

From the looks of it, the Cub is in stable condition, but unfortunately, I haven't tested it yet. 

Recently, I went back over my board and resoldered the bad pads. I also went ahead and rewound the toroids since I didn't scrape off the enamel properly. The board looks 10x better and now all that's left is to clean off the excess flux - and test to see if it works.

For anyone wondering how I solved my problem, I started a thread on QRZ.com with a little common sense to help. You can find the posting here. What started as a simple question about testing tools soon turned into a diagnosis forum (also, just build a proper dummy load/wattmeter!). Other hams began offering me helpful tips and possible problems, and the number one problem was my solder connections, followed by my toroids.

Fixing both, I opted to uninstall the BNC connector. I just didn't feel comfortable mounting it to the board, so I opted for the RCA jack. Amazon sells adapters so this won't be too much of an issue for me. 

In addition to fixing the board, my Hammo Can is fully complete! Running between 12.6 and 13.8V at 15Ah, I have calculated and estimated that it will run for about 3 hours continuous on transmit and about 13 or 14 hours on standby. This, of course, is if I use my TS-660. On my FT-2200, I expect that the battery life will be much shorter. I have an additional 3.1A coming off of a USB accessory plug, but this shouldn't be too much of an issue. It is a little heavy, but it weighs as much as if it were full of ammunition. Charging time is about 15 hours max, and the most I could get out was 13.8V on one charge - perfect for ham radio! The wiring harness isn't too bad - I solved the bunching-up issues with nothing but zip ties. With some help, the wires lay nicely in the case.

Believe it or not, there is still room for cables. There is even room for the charger which is not very large at all. Now I have a power supply I can use at home or in the field, and here's the best part - there is NO switching noise at all on the Kenwood! There's nothing but a beautiful and flat noise floor. Bye-bye, Lyle/Pyramid 30A power supply!

How much was it, you ask? I'm putting it around $50 or $60 - exactly how much I wanted to spend, and exactly how much anyone should spend on power. Here are the links to everything I got:

• Battery: Mighty Max 12V 15Ah
• Charger: 12V SLA Charger with Short-Circuit Protection
• USB Port: 3.1A USB Hub w/ Fuse
• Binding Posts: 10pcs 4mm Binding Post
• Switch: Heavy-Duty Rocker Switch, ON/OFF
• Ammo Box: Plastic Ammunition Box Waterproof
• Wire Connections: 79-Piece Assorted Kit Crimp Connectors
• Wire: 12AWG Red and Black

Here are some photos:

I used this power supply to talk to Italy, so I'd consider this a huge success! It's easy to build, so if you're going out to the field soon or helping with EMCOMMs, consider building one of these. For a bit more, you could put it all in a metal ammo can rather than plastic, but either will work just fine. I'd recommend recharging it after you come back from your adventure or connecting it to a float charger. This will give you a full battery for next time!

The Cub Is...Dead???

 Yep, you read the title correctly.

The MFJ Cub is dead.

At Long Last, The CUB!!! (And how to make a dipole for it!)

 At long last, I have you now, Cub! After 2 or 3 weeks of waiting for it, I'm hoping it will be worth the wait.

In the meantime, I looked over the PDF instructions to see what I was working with. I will need some alignment tools, and some might just be rudimentary. I did manage to find my NanoVNA in a drawer on my workbench, so this week has been good... up until I began running a low grade fever and felt like I was going to pass out at any given moment.

Not sure what happened, but you can all breathe - it was NOT Covid. My guess is that I got overheated at band practice or something else. I'm not quite sure what happened with me, but I'm feeling just a bit better.

MFJ Cub: Prospective QRP Project

Well, it's been a while, hasn't it? I guess I'd better start posting again about my latest adventures...

Recently, I've been considering doing one of many projects. I had the option to build my own travel trailer, give a complete makeover to my car, or pursue my hobby of amateur radio further. All the pursuits above have one thing in common: cost.

With that in mind, I settled to invest in my hobby.