Monday, November 11, 2019

3D printed desktop rack for KX3/PX3

Having tried my hand at 3D printing and knowing the difficulties of achieving an acceptable end result I am always amazed at the innovative products from those who have more sticktuitive-ness than me.

Robert K5TD makes me wish I had a KX3. His own design of a 3D printed rack beautifully shows off the radio and panadapter and, from observation, increases the ergonomics of operating them both together, especially with all the cabling required for digital modes.

Friday, November 1, 2019

Results with Ultimate 3S and 5-watt 630m amplifier

Not yet housed amp; muffin fan (upper right)
Finally, all three components came together: the 630m LP filter for my U3s, the 5-watt amp kit from G0MRF and the loading coil for my 80m dipole (configured as a top-loaded vertical on 630m).

The hold-up was the coil, solved by a trip to Home Depot. I had repurposed last year's bucket (coil form) so had to make a new one. Looking at my write-up from back then I saw that I needed 25 turns of 12g wire to bring the antenna's SWR down to less than 2:1 so I made that my starting point for the new coil. To my surprise, 25 turns was exactly what was needed this time as well.

Wednesday, October 30, 2019

Video in the making: SW-3B QRP transceiver

UPDATE: No video possible at the moment. The screen capture software was set to capture screen activity in a file format incompatible with my video editing software. I had hoped to have both screen activity (logging software) and the video of the radio itself represented in the video simultaneously. I may make another attempt at a later date.


In the few months since first posting about it, the write-up on my SW-3B has become one of the most viewed pages on this blog.

More than the usual number of comments and a good amount of emails have shown me that there's quite a bit of interest in this small triband transceiver.

Tonight I hope to come as close as possible to putting you in the driver's seat and demonstrating the radio's characteristics when operating semi-high speed CW. The final hour of the weekly CWT Sprint will be taking place tonight from 0300-0400Z. That's 10pm to 11pm in the US Central time zone.

UPDATE: I'll be operating on 20m in the 6 Nov CWT Sprint from 1900Z-2000Z.

I'll be delaying an episode of Peaky Blinders for the sake of radio but only if an approaching cold front contains rain with no lightning. Electricity in the sky will delay the video till next Wednesday.

Operation will be on 40 meters, 5 watts, with a dipole up 33.5m. That's 110 feet to you fellow 'mericans.

I'll be mostly search-and-pouncing but may get cocky toward the end and try running a frequency. Speeds will be 28-30 wpm so viewers should get a good idea of keying and T/R turnaround times, receiver bandwidth, etc.

N3FJP contest software will be keying the rig; copying will be performed by those appendages on each side of my cranium.

If you feel like joining the fun, please call me - our contact will likely make it to YouTube and then the sky's the limit - Hollywood will no doubt call the next time they need a pair of fine CW ops for their next Titanic movie. If the scene is dark enough, I'm pretty photogenic.

Monday, October 28, 2019

Lowband antenna up; works VP6R on 160m

We just returned from vacation Saturday so I was late to the VP6R party - but not too late.

By Sunday afternoon my lowband antenna existed as an 80m dipole, up 110 feet and fed with ladder line for operation on all bands above 3.5 MHz. Tomorrow I'll configure an alternate feed method which will allow me to use the antenna as a top-loaded vertical on both 160 and 630 meters.

But this morning, just before sunrise, VP6R was thundering in on the band formerly known as Top and, much credit to my AT2K tuner, I was almost able to make a nearly-acceptable match. It was 3:1 but, hey.

Power levels above 35 watts caused my Flex to shut down at that SWR, so I called with what I had and managed to get Pitcairn on 160 for a New One on that band. I believe Nodir EY8MM was at the key, performing radio magic by pulling me from the ether like a rabbit from a hat.

Sunday, October 13, 2019

Some surprising results with LP filters from Ultimate 3S

Nine low-pass filters were granted temporary reprieve from duty in the Ultimate 3S today to do brief time as test subjects in my NanoVNA.

In seven of them, the results were predictable and acceptable. The other two - for 20m and 60m - showed poor performance for their respective bands.

In addition to the need to investigate why these two bands are poor, I gleaned another tidbit of useful info: that I don't really need a filter for each band. For example, the 30m filter would perform well with 7 MHz selected as the band of operation...minimal insertion loss and excellent suppression of frequencies above 10 MHz.

Similarly, the 80m filter performs perfectly well for 160m operation. In almost all cases, a lower filter could be used for a higher band with no penalty for this substitution.