Studying the 2-m and 70-cm repeaters I can excite every day from home (IM98ri99) [that is, without the help of tropospheric ducting] I have found that about half of them are behind rather tall mountains; I suspect the knife-edge effect or diffraction on the crests of these mountains is the reason. In the picture, a 1050-m peak (Penya del Salt de la Mort, EA5/AT-056, IM98mi36) at ~40 km from my place is possibly the reason why I can reach a REMER repeater at Ardal (EA5/AB-032, 160 km, IM88ti76) from home every day. Here is a heywhatsthat.com profile for it.

Here's another example:

I reach the (wonderful) 2-m and 70-cm repeaters at the summit of Cocoll, 1048 m [ED5YAM, IM98wr26], 52 km from me, not despite the ~1400-m ridge 38 km from me [IM98vp15, part of the Aitana range], but probably because of it. 

So, perhaps, 2-m and 70-cm ham radio is not only about line-of-sight, tropospheric ducting, or satellites. You can be surrounded by mountains and still reach far with their help.

[Picture by Omar Sakhi, https://www.wikiloc.com/hiking-trails/jbel-foughal-1532m-88397381]

A 2-metre-band repeater that gives a lot of joy to the people of the western Mediterranean (Valencian Country, Murcia, Andalusia, Sardinia, Balearic Islands) when there is tropospheric propagation is in Morocco. It is an R5A, 145.7375 MHz, with a 77 Hz tone. It is clearly distinguished by a long tail, two seconds or more, and sometimes you can hear it getting stuck (feedback, due to some problem with the cavities). But where is it really? They usually say it's in Oujda. The Royal Association of Radio Amateurs of Morocco places it in the city. Repeaterbook says this location is approximate, and indeed Oujda is in a fairly flat area. The same website of the Moroccan Association says it is in IM75UB. But Oujda is in IM94. A few months ago, Angel, EB7BFP told me that the repeater was on a very high mountain, 2,400 m. And that it was near Taforalt (=Tafoughalt?). It is a mountain area, but Tafoughalt is in IM84. Another day, Mustafa, CN8GC, with a walkie in Saidia explained to me that the repeater is actually on a mountain. He emailed me with the name and location: Aïn Almou, ~1400m asl, about 25 km NW of Oujda (also IM84). I think Aïn Almou is a tourist place. It is near a higher peak called Jbel Foughal [OpenStreetMap and GaiaGPS of the area where there is also a summit called Foughal]. This Wikiloc route to Jbel Foughal shows a picture some antennas at the secondary summit. Many local names are Amazigh. Amazigh has a characteristic circumfix that adds a t- to the beginning and the end of the word (I think it's for the feminine). There are names like that throughout the Maghreb (Taourirt, Takoumit, Talsint, Tounfit) and even in the Canary Islands (Tacoront(e), Teguest(e)), etc. Well, if we take "foughal" from Jbel Foughal and the circumfix ... ix "t(a)foughalt". Interesting! Possible confusion? In the absence of more information, it remains unclear to me where this fantastic repeater is. If anyone knows anything else, it would be greatly appreciated. In the meantime, we'll enjoy it.

Un repetidor de la banda de 2 metres que dóna moltes alegries a la gent de la Mediterrània occidental (País Valencià, Múrcia, Andalusia, Sardenya, Balears) quan hi ha propagació troposfèrica és al Marroc. És un R5A, 145,7375 MHz, amb subtò de 77 Hz. Es distingeix clarament per una cua llarga, de dos segons o més, i a voltes s'escolta com s'enganxa (es retroalimenta, per algun problema amb les cavitats). Però on és realment? Normalment diuen que és a Oujda. L'Associació Reial dels Radioaficionats del Marroc el situa a la ciutat. Repeaterbook diu que aquesta localització és aproximada, i, de fet, Oujda és en una zona prou plana. La mateixa web de l'associació marroquina diu que és a IM75UB. Però Oujda és a IM94. Fa uns mesos, Àngel, EB7BFP em va dir que el repetidor era en una muntanya molt alta, de 2.400 m. I que era prop de Taforalt (=Tafoughalt?). És zona de muntanya, però Tafoughalt és a IM84. Un altre dia, Mustafa, CN8GC, amb un walkie en Saidia em va explicar que el repetidor és a una muntanya, en efecte. Em va enviar e-mail amb el nom i localització: Ain Almou, ~1400 m, a uns 25 km al NO d'Oujda (IM84 també). Crec que Aïn Almou és un lloc turístic. És a prop d'un pic més alt que es diu Jbel Foughal [OpenStreetMap i GaiaGPS de la zona on també hi ha una elevació que es diu Foughal]. Aquesta ruta de Wikiloc mostra una foto amb antenes en el cim secundari. Molts noms locals són amazics. L'amazic té un circumfix característic que afig una t- al principi i al final de la paraula (crec que és per al femení). Hi ha noms així a tot el Magrib (Taourirt, Takoumit, Talsint, Tounfit) i fins i tot a les Canàries (Tacoront(e), Teguest(e)), etc. Doncs bé, si prenem "foughal" de Jbel Foughal i el circumfix... ix "t(a)foughalt". Interessant. Possible confusió? A falta de més informació, continua sense quedar-me clar on és aquest fantàstic repetidor. Si algú en sap alguna cosa més, serà benvingut. Mentrestant, en gojarem.

On Saturday March 6, 2021, the bad weather that had been forecast had not arrived yet, and I decided to climb up to another "easy" SOTA peak, the highest peak in Serra de Cofer, 765 m (EA5/AT-079), never activated before. To get there, I drove to Fondó de les Neus and then to La Canalosa, and from there to Cases de la Inquisició at Alt del Conill.

I followed a path I took from Wikiloc .  

Most of the time there was no clear path; sometimes, piles of stones give an indication. One simply follows the crest. Sometimes small piles of stones mark the way. There is even a few with green paint.

As part of a plan to attract more people to amateur radio, I designed a "flash" activity where anyone with a personal mobile radio (PMR 446) handset could participate; as you know, anyone can use this band under certain conditions (500 mW, unmodified handheld with non-detachable antenna). After announcing my activity to amateur radio operators in the area and other friends, and after getting sufficient positive responses, on Saturday February 20, 2021, I climbed up (again, yes, we're still COVID-locked inside our municipalities) to Serra Mitjana (SOTA reference EA5/AT-099, locator IM98qj81) with a few "legal" PMR handsets, some very old. I finally only used the Cobra MicroTalk MT600 on the left. 

I arrived at the summit around 0845Z (in the picture, the peak is the one on the left). It was foggy and the fog lifted only when I was about to leave. 

I told everyone that I would be on channel 5, and started contacting people. After about 2 h on channel 5 and 6, I logged 15 contacts, all of them line-of-sight if I am not mistaken. No tropospheric ducting (although there was a bit of it, as I could clearly hear operators from Eivissa, 180 km away, on the 2-metre band). Of these, only 4 were "legal", in the sense that were done between two PMR-complying handsets in hand, but maybe three more were actually very close to legal. Of those four "legal" contacts, two were with people holding an amateur radio licence. The "not-so-legal" contacts were with stations with roof antennas or bigger powers. The farthest "legal" contact was 18 km away, and the distance doubled for the "not-so-legal".

Serra Mitjana is inside the limits of Alacant, a city with about 330,000 inhabitants; here is a picture I took weeks ago from the summit on a sunny day.

This that many other people using PMR handsets were in range: children (at least two groups), employees of a nursing home (with whom I negotiated moving to Channel 6), a sports store, etc.  This made contacts difficult sometimes. Maybe they had CTCSS or DCS tones on and could not hear me.

As I promised, I will prepare a diploma for everyone who participated, in two categories: "restricted" and "unrestricted". 

When I arrived back at the car (see picture from where I parked it) I decided I will call this "I Diploma PMR Serra Mitjana d'Alacant". Maybe there will be a "II Diploma".

The take-home message? There is a lot of fun to be had by radio-oriented "ordinary" people with very cheap, easily available, off-the-shelf handsets, and there is a chance that this may get them interested in amateur radio. Having said that, I must confess that I had all PMR 446 sets at home for more than a decade, and it was not until my son got a Baofeng UV-5R and I found out that it could work ham bands that I decided that, hey, I could get a licence, and I did (and my son did too). I will think of a plan.

On Friday, February 6, I made the decision to hike on Saturday, February 7, to SOTA summit EA5/AT-099, Serra Mitjana, with a 7023.2-kHz 0.3-W Pixie (which I bought pre-assembled from a Chinese online shop for about 8 euro) and a center-fed half-wave inverted-V dipole. 

COVID-19 regulations in force restricted me to summits inside my municipality (Alacant). There are two; the other one is Fontcalent, EA5/AT-036, which is a harder climb. I had already activated Serra Mitjana three weeks ago (never activated before) with my Xiegu G90 and a whip antenna, but I thought it was better to hike to a known summit for the Pixie experiment. And this one was great to spread a dipole, nice and flat at the 407-meter top. No trees, though, so I was expecting to keep the mast up using the two branches of the dipole and the feedline in a triangular configuration.

My plan was to be there at around 0900Z, but I arrived a bit earlier, around 0815Z, after a rather leisurely 25-minute hike from where I parked the car, about 30 minutes from home. It took me a little time to erect the dipole without fixing the mast (a telescopic, 5-meter fiberglass fishing rod — but I didn't use the last meter or so, too thin) to anything, but I was lucky that there was no wind at all and it nicely stood up during the whole activation.

I knew that receiving with a double-side-band conversion receiver with no audio filtering such as the Pixie was going to be tricky, as would also also hear operators in a wide, 6 or 8 kHz band around the beat-frequency.

I calibrated the Pixie at home, using my IC-725 and a NanoVNA to generate a fixed-frequency carrier (I also found that my IC-725 was some hertz off on the way). Its transmit frequency was 7023.2 kHz. I marked the dial (that changes the frequency of the beat oscillator by about 1.5 kHz), and made a small mark where I would comfortably hear a 850 Hz tone from stations that zero-beat me. Of course, I would also hear stations 1700 Hz above, but moving the dial and checking how the tone changed would tell me.

By the way, another nice (but laborious) way to calibrate it is to listen, pick up call signs, zero-beat them, and then check frequencies in a cluster or the Reverse Beacon Network which automatically spots CW, bearing in mind that you hear stations on both sides of the BFO frequency. A tuned music keyboard and a list of frequencies can also provide audio frequencies to compare with what one hears.

To power it, I used a pack of 2×3×4,5 V batteries that I had prepared for a different purpose. I'm sure it would have worked as well with just 3×4,5 V, at half the weight. To listen in, I used a foldable AKG headset.

I spotted myself using the SOTA Spotter application on my mobile phone, called CQ SOTA very slow, and colleagues started to reply, even pile up. I had a hard time picking them up from all the other stations in frequencies around (but not as hard as I expected), and (as usual) made a bit of a mess of the pile-up. I ended up logging 7 QSOs, EA and F, between 310 km and 780 km away, with very understanding colleagues:

To make things worse, my antenna connection was a bit flaky (it had desoldered, as I found when I came back home), and I did break my 3D-printed Chinese key at ~09:40Z, which ended the CW part of the activation.  Clearly, I was hitting it too hard, and perhaps part of the chirp was due to a bad contact. I also lost one of the lenses off my glasses, but that is not a radio-related incident (I searched for it for about 45 minutes while doing some 2m FM QSOs with my FT-60, no luck).

F5LKW Roger, a triple SOTA goat (>3×1000 activations!) was so kind that he even put together a nice video of part of my activation (https://www.youtube.com/watch?v=ebwHqVjcjYQ) which clearly shows the mess I made but also the terrible chirp I had.  Roger had already done a Pixie activation himself in 2017 (pictures in https://sotl.as/summits/F/AM-694). 

The take-home (or take-to-the-summit) message? If you're lucky and your Chinese Pixie works well [1] (which you can test and calibrate at home), bring a nice straight key, batteries, headphones, and a proper half-wave dipole to a summit, and you might be surprised at what you can do.

[Edit, March 17, 2021: lots of people have taken their Pixies to SOTA activations. According to the spots posted on Twitter, about 40 people have self-spotted themselves activating a summit with a Pixie]

[1] The pixie I brought to Serra Mitjana was the second Chinese Pixie I had bought. The first one worked but came with a broken 47 kΩ BFO potentiometer. Having no replacement for it, I removed the potentiometer, and installed two resistors I had (22 kΩ and 33 kΩ) instead, to simulate it being roughly half way. Its RX frequency is 7023.68 kHz, 540 Hz above the TX frequency, 7023.14 kHz. A tone of 540 Hz when a station zero-beats me (chirp allowing) is a bit 'bass' but should work. One problem, of course is that I will hear an operator at 7024.22 kHz ("image") with exactly the same tone. With a variable potentiometer, moving it a bit clearly shows which one is the right one; with fixed resistors, one has a 50% chance.

I needed a blog, so here it is. An amateur radio blog. It will mostly be in English, but there will be posts in other languages. I needed a place to collect ideas and information that I have posted, mainly in Twitter, in hopes that they will be more useful (if they are at all) when put together in a blog. We'll see.