The personal website of Scott W Harden

Started Transmitting Letters

I finished writing the microcontroller code to read the GPS time and only start transmissions when the minutes value ends with a zero. The signal now stacks nicely in 10-minute grabs. Now that GPS and the oven is working well I've started sending my call sign (AJ4VD).

AJ4VD spotted in Pensacola, FL (W4HBK)

First spot occurred while I was actively adjusting the transmission length

AJ4VD spotted in Greensboro, NC (WD4ELG)

5x frame stack (mean frame) from the WD4ELG grabber reveals the AJ4VD signal much better, and confirms the GPS timer is working well.


I got OOK and FSK working together (the S shape in the middle). I'm also now using a crude oven, but am not sure yet how stable frequency is over long time spans.

AJ4VD spotted in Pensacola, FL (W4HBK)

AJ4VD spotted in Greensboro, NC (WD4ELG)

I kept thinking my oscillator was drifting frequency because the line wasn't straight. Turns out it was my curved monitors!

Amplifier Improvements

I improved my amplifier (now output 500mW) and am impressed how well my attic dipole is doing! It runs east/west so it radiates north/south. I saw my signal on a few more grabbers.

AJ4VD spotted in Northwood, OH (N8NJ)

AJ4VD spotted in Las Cruces, NM (WA5DJJ)

AJ4VD spotted in Florida (WD4AH)

This grab shows a nice airplane reflection in the middle

AJ4VD spotted in Ontario, Canada (VA3ROM)

AJ4VD spotted in Pensacola, FL (W4HBK)

This 8-hour grab reveals when my AC kicks on and off and demonstrates the necessity of ovenizing my setup. It's the signal around 10,139,980 Hz.

QRSS Spots

This week I strung-up a 30m dipole in the attic and built an oscillator, keyer, and amplifier (all as separate modules). I finished the amplifier this morning and spotted the signal (the rectangular squiggle) on two grabbers. I was running 3 PPV into 50 Ohm so I think that's about 22 mW.

AJ4VD spotted in Pensacola, FL (W4HBK)

AJ4VD spotted in Greensboro, NC (WD4ELG)

Bone Marrow Transplant Complete!

After 23 days living in the hospital I’m happy to report my bone marrow transplant is looking good, and I’m free to continue recovering at home! I’m not going to sugar coat it: this ordeal was rough. However, I planned and prepared well for it, had a lot of fantastic support along the way, and I feel great about how well everything went! It couldn’t feel more amazing to finally be home again. The air conditioning, my couch, my TV, my pillow, my high-speed internet! It’s great to be back.

For those of you finding this page for the first time, I just finished an autologous bone marrow transplant to treat a condition where I make abnormal cancer-causing white blood cells. To do this some stem cells were collected and frozen, then strong chemotherapy was used to kill all of my bone marrow (where blood cells are made) to the point my body could no longer make any blood. During this time my white blood cell count went to zero, and I required blood infusions to keep me alive (thanks all you blood donors out there!). I was then infused with stem cells that were able to start growing new bone marrow. I have a brand new immune system now (just like when I was a baby) and it will continue to grow over the next few months, but I have to keep it safe by wearing a mask and limiting my exposure with other people while it matures.

I made an infographic to show my bloodwork during transplant. What, you didn’t think I’d try to data mine stuff from my procedure? In the bone marrow transplant world, stem cell infusion (transplant day) is what everything is centered around. I was infused with strong chemotherapy multiple times a day from days -6 to -1 to kill all my blood-producing bone marrow. Day zero I was infused with previously-collected stem cells, and celebrated a new birthday for my immune system. Since the old bone marrow was dead and not producing any white blood cells, my circulating blood cells slowly dropped off until they reached zero. Note that healthy adults have a white blood cell count of 5-10 (thousand/µL). It was a scary feeling on day +5 knowing that I had a white blood cell count of zero! The bone marrow transplant floor is largely sealed and isolated, visitation was is highly restricted, and I was on multiple antibiotics, antifungals, and antiviral medicines to get me through it. On day +9 I got the first hint that the transplant was working, as my white blood cells were just barely detectable. This confirmed that stem cells had matured into white-blood-cell-producing bone marrow (engraftment), and as my levels climbed I felt better and better.

Now that the core of my bone marrow transplant procedure is over, I don’t plan to continue updating this web page regularly. The procedure isn’t a sure bet at curing my disease, but it’s the best shot I’ve got, so I’m just going to wait it out and take the best care of my body I can and hope for the best. There’s a chance I could need additional treatment some day (CAR-T immunotherapy, an allogeneic bone marrow transplant from another person as a donor, or additional chemotherapy) but for now I’m taking it easy, and if this page remains dormant that means I’m living a normal life!

Update: one week later...

Thanks to all the friends and family that supported me during my treatments both locally and from afar. This experience was challenging but doable, and I attribute a lot of my success to your support and encouragement. I hope I won’t need any more serious treatments from here, but even if I do I know I’m prepared! The whole team at the UF Health Bone Marrow Transplant Unit was amazing too, and I couldn’t be more grateful and impressed with the awesome treatment I got along the way.

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