All posts by Matt W6CSN

Field Reports, Guest Posts, Morse Code, Portable, POTA, QRP, Travel

UK POTA Rain and Shine

June 22, 2024 Matt W6CSN 6 Comments

Bletchley Park

Most readers of this blog are probably familiar with Bletchley Park and the significance of this place in breaking the codes used by the axis military forces during the second world war.

The electromechanical systems developed and used here to aid the codebreakers in their daily work led directly to the electronic digital computers of the mid-twentieth century, and then to the modern world as we know it.

After boarding the London Northwestern Railway at Euston station, the hour long train journey took us from central London, through the suburbs, then the pastoral English countryside to the station at Bletchley, just south of Milton Keynes.

Bletchley Park is a five minute walk from the train station at Bletchley, the town of the same name. In keeping with the formerly clandestine nature of the work at Bletchley Park, there are no loud signs to welcome you, just the Union Jack flying over the nondescript visitor center in Block C.

Exiting the visitor center, any ham will quickly spot the three-element SteppIR Yagi perched atop a roof-mounted tower. Also from the tower, a folded dipole extends over the the Block B building which houses the Alan Turing museum exhibits. The other end of this antenna farm is plugged into GB3RS, the amateur radio station for the National Radio Centre of the RSGB.

The friendly and helpful staff of amateurs at the NRC played a crucial role in my hoped-for plan of activating Bletchley Park for Parks On The Air.

Surprisingly, the POTA page for GB-0507 showed only a handful of activations of this iconic location. Seeing as this is a heritage site, I sent an email to the NRC about week before my visit asking for advice on how to be a welcome guest POTA operator.

Note, the NRC is colocated on the grounds of the museum but they are not a part of Bletchley Park. The NRC is a separate organization.

Martyn G0GMB, the Director of the NRC, kindly responded to my enquiry and informed me that individual amateur radio activity is not generally permitted on the grounds of Bletchley Park due to the number of visitors they receive and concerns about RF safety. This could explain the low number of activations.

The sharp eyed will spot the GB3RS beam across the pond.

Martyn suggested I could set up in the overflow car park few minutes walk down the road from the visitor center. While not on the grounds of Bletchley Park proper, the parking lot operation would still be in the spirit of POTA and would reasonably count as a valid activation location.

When I arrived at Bletchley Park on Friday afternoon, I was met by Mervyn G4KLE who was expecting me thanks to a note left by OM G0GMB. Mervyn asked where all my equipment was and I motioned to the pack on my back.

Because my radio and antenna was a low impact, minimal footprint QRP setup, I was told that I could make use of the picnic table just out the side door of the GB3RS shack, with my antenna setup just beside it. This dead-end spot was not on any of the paths frequented by park visitors and my antenna would not be easily visible.

This was a much better arrangement than trying to activate from a car park without a car! I quickly deployed a GRA-GNT micro tripod with center spike pushed easily into the soft ground. The GRA-7350T loaded vertical and a set of short radials provided an SWR of 1.05 to 1.

I chose the QMX as a travel radio while in Britain because with it, the overall kit is very lightweight and compact. With the exception of the tripod the whole kit fits in my carry-on. The GRA-GNT antenna mounting kit has to fly in checked baggage due to several aggressive looking spikes that would certainly be flagged by airport security. Continue reading UK POTA Rain and Shine →

Field Reports, Guest Posts, News, Portable, POTA, QRP

The Adventure You Get

May 28, 2024 Matt W6CSN 10 Comments

Many thanks to Matt (W6CSN) who shares the following post from his blog at W6CSN.blog:

The Adventure you get is not always the adventure you expect. Recently I’ve been plotting a unique activation of the De Anza National Historic Trail, but that particular POTA activation is going to need a good antenna and just as importantly, time.

This day afforded a few hours in the morning for outdoor radio but not enough to retrace the steps of the De Anza expedition. Instead, I headed down to the San Francisco Bay side for a quick outdoor amateur radio session.

Marina entrance light from years gone by

Since it was was a Saturday, my usual spot at Presidio East Beach was heavily impacted by weekend recreation enthusiasts, so I continued for a quarter mile to the practically empty parking lot east of the St. Francis Yacht Club.

Small dry beach on the marina side of the jetty

Thence on foot past the old stone light tower and the clubhouse of the Golden Gate Yacht Club, you find yourself of the path to the end of the breakwater where a unique art installation sits.

The Wave Organ is a curious sculpture that uses tubes and cavities between old cemetery stones to channel and amplify the watery sounds of waves as the tides move in and out of the Bay.

Surrounded by saltwater at the end of this jetty, which by my reckoning is within the boundary of the Golden Gate National Recreation Area (US-0647), this location was perfect for the “no impact” operation afforded by the Elecraft KH1.

This granite wall served as the operating bench

My plan was to see if I could complete an activation of making 10 contacts entirely by hunting other POTA activators, perfectly reasonable given it was a weekend with no geomagnetic storms to disrupt radio propagation.

An entire station in the palm of your hand

What I did not count on was that it was a contest weekend with both 20 and 15 meters wall-to-wall with rapid fire contesters. As a QRP station, finding the POTA needles in that haystack was going to be tough.

The wave organ is a naturally contemplative environment

I retreated to 17 meters which should offer good daytime propagation and no contesters. There on 18 MHz, I was was able to collect five park-to-park contacts in a span of 23 minutes.

At that point I’d exhausted all of the 17m active CW stations on the POTA spots page and didn’t really have time to wait for more to show up. Therefore the “all hunting” activation strategy was abandoned and I commenced calling “CQ POTA.”

A fresh charge delivers nearly 6 watts into a matched antenna on 17m

The activation was “validated” with a call from Dave, AA7EE as the 10th QSO and then completed with one more park hunted, K9DXA in US-1001. Most of the contacts were with stations east of the Rockies.

http://tools.adventureradio.de/analyzer/

One thing I learned from earlier outings with the KH1 was to not cut the log sheets too small, as might be suggested by the lines printed on the page. Without enough paper under the top and bottom tabs of the logging tray the sheets can easily be caught and snatched away by the wind.

Leave enough margin on the logging sheets and they are easily secured in the tray, even in the face of brisk Bay breezes.

Looking across the marina entrance toward Fort Mason

The “hunting only” activation plan didn’t quite work out but it was a great time out playing radio at scenic spot in San Francisco Bay.

Sailing season is well underway on SF Bay

While I didn’t expect to activate from the wave organ today, it turned out to be a fun adventure and an excellent spot from which to get on the air with the KH1.

73 de W6CSN

Field Reports, News, Portable, POTA, QRP

Change Is Good

May 1, 2024 Matt W6CSN 7 Comments

by Matt (W6CSN)

Recently, OM Witherspoon (K4SWL) wrote a blog here and shared a POTA activation video in which he described the benefit of changing up your operating location within a large park to keep things fresh or simply to be able to activate within a given schedule.

Activation zone looking over the Pacific

That got me to thinking about my own “home” park, Presidio of San Francisco US-7889, a large park which is also part of an even larger reference, Golden Gate National Recreation Area (GGNRA) US-0647. Recently my XYL, who is very patient, has been subjected to my complaining about being bored by doing the same activation over and over.

My typical POTA outing is after work, I drive ten minutes down to the East Beach parking area, set up a base-loaded vertical on the roof of my car and plug in the trusty FT-818. Mind you, this is not a bad setup. The location combined with repeatable antenna installation reliably produces contacts and I usually have a complete activation in about 30 minutes.

The XYL’s suggestion was, “hey, why not play radio somewhere else?” and K4SWL’s blog and video were an inspiration as well. So I left the FT-818 in the shack, packed up a QMX kit, and headed for the high bluffs in the Presidio that overlook the Pacific Ocean to the west. I setup on an out of the way granite bench that was part of a World War II memorial to servicemen who perished in the coastal waters of the Pacific.

My plan was to get on 15 meters in the hope of catching some early JA’s or other Pacific rim DX. The vertical antenna deployed easily and though the location was substantially protected from the strong wind gusts, I did stake the tripod down with a pair of tent pegs.

With an SWR of below 2:1 on 21 MHz I set to calling CQ and posted a spot on pota.app advertising that I was in US-0647 GGNRA, even though I was also still in US-7889. Turns out 15 meters was dead, for me at least. Not a single nibble after 15 minutes of calling.

After a QSY to 20 meters, another half hour brought in only four QSOs! This location and radio combo was certainly a nice break from the usual and even though the QSO pace was glacial, it was quite satisfying and refreshing to do something different.

Since the clock read just after 00 UTC there was plenty of opportunity to gather the needed contacts for a complete activation. If necessary I could even come out the next day before 23:59 UTC. But since I had no particular time constraint for the evening, I decamped for East Beach where I was pretty sure I could wrap up the activation in short order.

Even though I was back at my “usual” spot, starting the activation somewhere else was the change I needed to break the routine. Six more QSOs validated the activation in a matter of minutes. I swear being down close to the waters of San Francisco Bay adds at least 3db to my signal. There is a reason I frequent this particular spot.

I feel fortunate to have so many locations within US-0647 and US-7889 that are quite close to home. I plan to take advantage of this diversity of operating spots, knowing that the “East Beach Amplifier” is always available if my QRP is not cutting it.

72 de W6CSN Matt

P.S. I did, in fact, log this activation as a two’fer.

Articles, Field Reports, Guest Posts, How To, Kits, News, Portable, POTA, QRP, QRP Radios, Reviews

QMX – From Kit to Field!

March 1, 2024 Matt W6CSN 16 Comments

by Matt (W6CSN)

The Radio

The QMX by QRP Labs is a five band, multi-mode radio introduced by Hans Summers G0UPL at FDIM in 2023. The QMX is the next logical step in the radio development journey at QRP Labs, bringing together the innovative approach to FSK modes like FT8 from the QDX and the CW performance of the QCX series. This is all done in same enclosure as the QCX-Mini which is not much larger than a deck of playing cards.

Size of the QMX compared to standard deck of playing cards. — The QMX is about the size of a deck of cards.

The keen observer will notice that the QMX also sports a built-in microphone which, along with associated circuitry, supports future introduction of voice modes by way of firmware update. Other notable features include SWR metering with protection as well as solid-state “PIN” diode T/R switching, plus the option for “high band” coverage of 20 through 10 meters in addition to the original 80m-20m version.

Most hams have, at one point or other, forgotten to throw the antenna switch, adjust the tuner, or even connect an antenna before transmitting. The SWR meter and protection really sets the QMX apart from earlier QRP Labs radios. There are plenty of sad tales on the QRP-Labs forums from QCX or QDX users that “smoked” the BS170 mosfet finals in a moment of operating into a badly mismatched load. It’s remarkably easy to do, ask me how I know!

The Build

Based on experience with the QCX-Mini and having put together several QDX’s, I admit to being hesitant to starting assembly of this radio. The level of integration in the QMX as a multi-band, multi-mode unit is probably the highest yet to come out of QRP Labs. The components that were merely small in earlier radios are absolutely tiny in the QMX, specifically the LPF toroidal cores. The main board, internal switching power supplies, display, and controls board are all sandwiched together in a tight fit for the custom enclosure.

photo showing a partially completed circuit board — Most of the electronic components installed on the main board.

The build started with a slow and methodical approach of doing a little bit each day and working in the morning when my mind was fresh and there was good light on my workbench, a.k.a. the dining room table.

The first “disaster” happened when performing the factory recommended modification to Revision 2 boards shipped in 2023. The mod calls for a protection diode to be installed across a SMD mosfet. Several leaded 1N4148 diodes were available in my “junque” box so I attempted to carefully fit one of these in the right position on the board. While soldering the diode in place I managed to lift C508, a microscopic .1uF SMD capacitor, clean off the board!

photo of circuit board with modifications — The suggested modification adding a protection diode.

Given the tools at my disposal, there was no way I was going to be able to get that capacitor back into place. Therefore, I grabbed a standard through hole .1uF cap and painstakingly got it connected in the right place, verified by lots of continuity testing.

Once finished with all the electronic components on the main board, I was feeling pretty cocky and also the completion of the project was more clearly in view. The cautious and methodical approach gave way to a faster build pace, which directly lead to the second “disaster.” While installing the headers that connect the main board to the display board, I failed to CAREFULLY READ THE ASSEMBLY MANUAL and soldered the male pin headers where I should have installed the female sockets!

This misstep might have ended the project right then and there if I had not at some point in the last year bought a proper desoldering tool. This is not an expensive automatic vacuum pump powered solder re-work stations, but rather a heating tip and manually actuated solder sucker built into one tool. Twenty-two unsoldered connections later, we were back on track. Continue reading QMX – From Kit to Field! →