Monday, February 6, 2023

The utility of Elecraft's CP1 bi-directional coupler with the tinySA

Set-up for measuring spectral output of 100W rig. Note the 100W dummy load behind the tinySA

This is an example of where the availability of a new item adds value to something that's been around a while. The new item is the tinySA - many hams now have one of these small spectrum analyzers/signal generators - and the old item is Elecraft's CP1 bidirectional coupler.

Questions I get whenever I post something related to the tinySA are:

  • Can I use it with non-QRP equipment?, and
  • How do I measure a transmitter's output to make sure I don't exceed the tinySA's 6dBm (4mW) max input?

I decided to use my tinySA ULTRA to measure the spectral output of my Yaesu FT-891 when operated at full power: 100 watts.

Thursday, February 2, 2023

FX-4CR transceivers about ready to ship

Yu BG2FX informs me that the FX-4CR 20-watt transceivers will begin being shipped on about February 4 and that they will be sent out in the sequence of when they were ordered. He expects shipping of this rig to be completed by February 15.






Wednesday, February 1, 2023

Today, 4 Feb: Atsena Otie Key

Cancelled due to high winds. Boats not going out.
The trip kept getting delayed 30 minutes at a time, then cancelled altogether.
Another time...

Atsena Otie Key is an unpopulated island-ghost town about half a mile (1 km) off the coast of NW Florida.

More to the point of this posting, it is also the main island for K-0234 and KFF-0234 and has never been activated for WWFF; and only two activations (38 QSO's) for POTA.

After obsessing about how to get all my gear over to the island key in a kayak, I found Captain Bob with a small skiff.

Captain Bob will take me over for $15, drop me off, and pick me up 4-1/2 hours later, hopefully before scurvy sets in.



Saturday, January 28, 2023

Photos from the Central Florida POTA meet-up

I didn't make a single contact at this POTA event, but had a great time.

The cool morning, pre-Winter FD event, took place at Colt Creek State Park and I finally got a chance to put a face and handshake to those I've worked numerous times, namely Jerry K7UPJ and Bill K4NYM.

Over a dozen stations were set up - band-pass filters did their job! - CW, SSB and FT8 were all represented on multiple bands.

I couldn't help but notice the correlation between POTA operating and RVing - many of those shown here roam the country, activating parks from coast to coast. 

The photos:

Wednesday, January 25, 2023

tinySA ULTRA in Spectrum Analyzer mode, with Index QRP+

I'm really liking the new ULTRA and am finally using it as a spectrum analyzer instead of just a sig-gen.

The new Index QRP+ has been daring me to measure its spectral output - and the ULTRA's latest firmware supports storage of the displayed traces as a bitmap file, saved to an included 32GB MicroSD card.

A combination of Elecraft's bi-directional coupler and my step attenuator knocked its 10W output down by 40dB, to 1mW.

For some reason, I saw no harmonics on 160, 80 or 40 meters so I brought out the big (comparatively) Rigol. Same thing - and something I need to investigate. Surely, there are harmonics being generated on these bands...

Incidentally, I looked at the other bands on the Rigol as well - the displayed traces were practically identical to those of the tinySA ULTRA.

So why buy a Rigol instead of the tinySA?