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

UPDATE:
 
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?