Ham Radio

... on ham radio TRX like Yaesu or Kenwood

The Begali HST III morse key is a single-lever paddle that also has a sideswiper mode built in: By flipping a switch on the key’s base, one can operate it as a sideswiper. But why actually is that switch needed? Well, a single-lever creates electric contact on either of two sides, which have to be distinguished, because one side tells the keyer to emit dots (dits) and the other to emit dashes (dahs). That’s why a stereo jack is used to connect to a TRX, because that jack can carry those two channels. When using the single-lever as a sideswiper, though, both sides are equivalent and should simply trigger a key-down. Straight keys can be modeled using a mono jack only. So, for using the Begali HST III in sideswiper mode, both contacts have to be routed the same way, while in paddle mode, they have to stay separate. That’s what that built-in switch is for.

On my Kenwood TRX though, I was disappointed to notice that sideswiper mode of that key doesn’t work: When I plug it into the straight-key socket of my Kenwood TRX, a continuous key-down is emitted! It looks like Begali decided to make both contacts equivalent by shorting them. But thinking of the design of mono jacks, where most of the jack consists of common ground while only the tip carries the channel, that means that if that stereo jack is plugged into a mono socket, a part of the body and the tip are short-circuit, which simply means: key-down!

So, after wrapping my head around this and getting in touch with my CW Elmer, Heinz OE3LHB, he told me he’d gone through that before, with his first-generation Begali HST and his Yaesu TRX. He sent me this sketch of the original wiring and the sketch of the wiring that is needed for sideswiper mode to work on those TRX that expect a mono jack on straight keys:

So, instead of shorting upper and lower contact, both contacts should be routed to the tip. If you look closely, you notice that the 2-pin on/off switch has to be replaced by a 3-pin on/on switch. The 1st-gen HST came without wiring, the YL/OM had to do the wiring themselves, so, this mod wasn’t overly complicated to do. But the HST III comes with the wiring realized on a PCB:

The procedure to implement the desired wiring is:

1. Find a 3-pin on/on switch with the exact same size specs of the original switch. I soldered the original switch out and made measurements with a caliper, it should resemble a 5×8 mm rectangle when viewed from the top. I found a matching switch here.
2. Make a third hole to be able to fit the third pin of the switch through the PCB.

   

3. Place the new switch on the PCB and screw the PCB back in. Only then start soldering the outer pins of the switch to the respective conductor paths. Take care to leave the middle pin isolated from those. (Maybe you should do #5 before this.)
4. Disconnect the switch from the bottom contact (BOT) by scratching through the conductor path. That is, only keep contact with the RING.
5. Connect the middle pin of the switch to the bottom contact (BOT) using isolated wire and a soldering eyelet. (You could also paint a conductor path at the left border of the PCB, if you can do this.)

By this, sideswiper mode finally works. I sent this mod to Bruna Begali and explained why we needed to do that, but I didn’t receive a reply. Maybe they use TRX that work with the original wiring, or that key is rarely used in sideswiper mode. I never use it as a sideswiper anyway, but at least I restored that option for me.

In June last year, when I talked to Hans, G0UPL, ordering his QCX kit at his booth at the Ham Radio fair in Friedrichshafen, he mentioned that there would be a 50 W PA kit coming out soon, and that stuck with me. Meanwhile, I noticed indeed that QRP is just no fun when no one is answering your calls—sorry for having to say this. I like to think of this as a kind of “Law of the Conservation of Effort”: If a DX contact is established, and one of the stations is QRP, then the other one is doing all the work and effort (in terms of operating a respectable receiving antenna and/or “having to crawl into the speaker”). Well, thinking of my main goals that led me to the QCX, which were

• assembling a TRX completely on my own,
• getting a lightweight TRX, no matter its power,
• having it only support CW,

wouldn’t there be a better follow-up step than

• assembling a PA kit,
• a lightweight PA such that QRP is no longer an option (hi),
• having it only support CW (not sure about this, though, but at least it’s marketed as “the QCX PA”).

So, I kept close eyes on the QRP Labs site in the recent months for signs about that PA, and finally, at the beginning of December, Hans announced that PA on the mailing list, and only about one hour later my order was through. I was one of the lucky ones that could include his enclosure kit before it went out of stock.

QCX mods

While I waited for the kit to arrive, I had time for preparation: The QCX needed a PTT mod to be able to provide a PTT signal to the PA; this is achieved by patching a stereo jack into the circuits (plus creating an outlet in the QCX’s enclosure) and adding a pull-up resistor. I also flashed the latest firmware release using an Arduino Uno as programming device, which might be a topic for a different blog post. The harder question to answer was how to get a cheap but still qualitative 20 V 5 A power supply for the PA. Luckily, I already possessed the Lenovo UltraSlim 90 W (20 V 4.5 A) notebook travel power adapter, which even included the option to use a wall socket or a standard automobile 12 V plug. Therefore, I could even go from a standard 12 V lead-acid battery. I only needed a non-standard DC barrel adapter, which took some extra time to arrive. While I was at it, I purchased a 3S LiPo battery pack with nominal 11.1 V to power the QCX itself with something lightweight; note that I measured up to 13.1 V fully charged, so using a fresh 4S pack might fry the QCX.

The PA kit arrived after Christmas, and I was again looking forward to the assembly process, which promised to be not as lengthy as that for the QCX. It took me about ten hours nonetheless, mainly due to assuming errors where there had been none. I will now go over some specialties that I had encountered during the assembly.

Änderungen seit 12/2019

Folgende 13 Rufzeichen sind verstummt:

• OE1FCQ
• OE1TAO
• OE1XXU
• OE2BLT
• OE2KUN
• OE3UP
• OE5ELL
• OE5LJL
• OE6XEE
• OE6XVE
• OE7SFI
• OE7WZH
• OE9MRV

Folgende 67 Rufzeichen wurden bewilligt:

• OE1GUC
• OE1IFR
• OE1LDE
• OE1MEW
• OE1VFX
• OE1VZG
• OE1WEH
• OE2KOM
• OE3BKR
• OE3BMT
• OE3EBI
• OE3FCQ
• OE3HAZ
• OE3HRX
• OE3JAL
• OE3JSH
• OE3KME
• OE3MDX
• OE3MUM
• OE3MVM
• OE3NLR
• OE3SDE
• OE3SNO
• OE3TDF
• OE6AHF
• OE6AHR
• OE6BLP
• OE6BSN
• OE6EUR
• OE6FBI
• OE6GDO
• OE6KLF
• OE6LUI
• OE6LXS
• OE6MMR
• OE7JCT
• OE7XOT
• OE7XZB
• OE8DDX
• OE8JAS
• OE8KYK
• OE8OPT
• OE8PEG
• OE8RAT
• OE8WLF
• OE8XFO
• OE8XPQ
• OE9ALJ
• OE9CHV
• OE9IHR
• OE9JUP
• OE9LEQ
• OE9LMV
• OE9LOG
• OE9MIE
• OE9MNR
• OE9RIR
• OE9RKQ
• OE9TSR
• OE9XFP
• OE9XFR
• OE9XFV
• OE9XGV
• OE9XPT
• OE9XVI
• OE9XVV
• OE9XYI

Quelle: BMVIT

Dieser Eintrag wurde automatisch erstellt. Angaben ohne Gewähr.

Änderungen seit 10/2019

Folgende 18 Rufzeichen sind verstummt:

• OE1AQP
• OE1HBU
• OE1HXC
• OE1MSA
• OE1THS
• OE1YCA
• OE2FGP
• OE3EVW
• OE3GGU
• OE3NSU
• OE5BHM
• OE5FJN
• OE5SNM
• OE5VML
• OE5XJN
• OE6RPC
• OE7BWJ
• OE9LHV

Folgende 60 Rufzeichen wurden bewilligt:

• OE1NSU
• OE2LAT
• OE2RPC
• OE3XPU
• OE4EIE
• OE4EVW
• OE4GGU
• OE5AIK
• OE5AMF
• OE5BPA
• OE5FGP
• OE5HKQ
• OE5HXC
• OE5JOH
• OE5LEC
• OE5LPO
• OE5NEO
• OE5RIH
• OE5ROR
• OE5TMP
• OE5XXF
• OE6BIG
• OE6MLG
• OE6PUM
• OE7AZO
• OE7CSM
• OE7DIO
• OE7DRT
• OE7FXE
• OE7KIR
• OE7LKT
• OE7LPR
• OE7OPV
• OE7RJU
• OE7SAE
• OE7SLF
• OE7SZT
• OE7TSJ
• OE8AOK
• OE8ELO
• OE8ETW
• OE8FTK
• OE8GGE
• OE8GWQ
• OE8IJK
• OE8IMR
• OE8ITG
• OE8KOR
• OE8MDM
• OE8PMR
• OE8PPL
• OE8RGR
• OE8SMZ
• OE8SNP
• OE8TKK
• OE8TOJ
• OE8TWR
• OE8WER
• OE8XDK
• OE8XOK

Quelle: BMVIT

Dieser Eintrag wurde automatisch erstellt. Angaben ohne Gewähr.

Änderungen seit 07/2019

Folgende 18 Rufzeichen sind verstummt:

• OE1BUR
• OE1FZU
• OE1MIK
• OE1NHC
• OE1VCC
• OE2JYM
• OE3DRC
• OE3FRS
• OE3GJB
• OE3OLC
• OE3VNA
• OE8XDK
• OE8XDQ
• OE8XOK
• OE9SCV
• OE9WSI
• OE9XFV
• OE9XGV

Folgende 71 Rufzeichen wurden bewilligt:

• OE1AHD
• OE1CHT
• OE1CPU
• OE1EWA
• OE1FPF
• OE1HAT
• OE1KCR
• OE1KMX
• OE1LEK
• OE1LYK
• OE1MGO
• OE1MSX
• OE1NCA
• OE1PIM
• OE1ROD
• OE1TNS
• OE1XBA
• OE2BLR
• OE2ESF
• OE2KPT
• OE2RMD
• OE2SNH
• OE2TPI
• OE2XAE
• OE2XHD
• OE2XLJ
• OE3DET
• OE3GKQ
• OE3LLQ
• OE3MIK
• OE3MYR
• OE3PLF
• OE3PWT
• OE3SMX
• OE3UZA
• OE3XKN
• OE3XKY
• OE4VCC
• OE4VNA
• OE5TXF
• OE6AGE
• OE6BBR
• OE6BKQ
• OE6BLN
• OE6BOT
• OE6BWE
• OE6FEF
• OE6GOR
• OE6GRZ
• OE6KFL
• OE6LOE
• OE6LUM
• OE6MDW
• OE6MEH
• OE6MEP
• OE6MJF
• OE6PMT
• OE6ROH
• OE6ROY
• OE6RTH
• OE6UXS
• OE6WCB
• OE6XRH
• OE7REF
• OE7XKO
• OE8ALZ
• OE8IMQ
• OE8PTP
• OE8RCR
• OE8UFO
• OE8XGF

Quelle: BMVIT

Dieser Eintrag wurde automatisch erstellt. Angaben ohne Gewähr.

(This time in English, as there isn’t that much mechanical vocabulary involved that I was too lazy to look up in the dictionary, as was the case with my report about building the folding hex-beam. )

Considering my root motivations that made me involved with ham radio, there were three main points I wanted to fulfill:

• Build (but not necessarily design) a TRX completely by myself to gain some making skills, and understand at least the main part of how that HF circuits work,
• Get a small and lightweight TRX for portable operations, no matter if that meant QRP or not,
• Have it only support CW to force myself using CW exclusively on the air, which is a requirement that became relevant to me when I started learning CW. (In addition, CW would help compensate for the QRP constraint.)

So, walking down the aisles of the HAM RADIO fair in Friedrichshafen this June, besides fetching my shiny new Begali morse key, I was looking around for the CW TRX kits, designed to be soldered and assembled by their new owners themselves. The first one I saw (model name skipped here deliberately) was already promising, but it lost against the QCX: The QCX is younger, it has less SMD components (only two, and they are already soldered onto the PCB), and it was way(!) cheaper, despite comparable features. The only advantage of the expensive kit was that one could change the band by replacing a small band-specific module. On the other hand, although the QCX is a one-bander only, with a price tag of only EUR 44.00, one could simply build another QCX for that other desired band. I decided to go for the 40 m variant, having the coming winter season in mind.

As a beginner, it was also important for me to be able to tune the finalized TRX without any troubleshooting that requires advanced electronics know-how, involving signal generators and oscilloscopes. The QCX fulfills this by offering a built-in signal generator and an initial tuning routine that YL/OM follows by adjusting some trimmers while watching an amplitude bar on the display.

Assembly

When the kit arrived with all its component parts, I was really looking forward to the assembly process. And indeed, it was a lot of fun, boosting my soldering skills with each installed component and checking each step with a jeweller’s loupe. The whole assembly took me about 20 hours, spread accross several tinkering sessions:

Änderungen seit 01/2019

Folgende 105 Rufzeichen sind verstummt:

• OE1AQB
• OE1BEC
• OE1CMA
• OE1CPW
• OE1CWS
• OE1DMU
• OE1FCS
• OE1FJU
• OE1GCS
• OE1GCW
• OE1GDW
• OE1HEU
• OE1HMS
• OE1HNU
• OE1KIC
• OE1MHA
• OE1MJW
• OE1MXC
• OE1OGW
• OE1PRA
• OE1UCS
• OE1WIB
• OE2EMJ
• OE2IFN
• OE2LRP
• OE2MON
• OE2SPC
• OE2TJN
• OE2UJL
• OE2VBO
• OE2XBB
• OE3CGB
• OE3CJ
• OE3DNW
• OE3FMA
• OE3FPU
• OE3FZA
• OE3IP
• OE3JFW
• OE3JS
• OE3KFW
• OE3LKC
• OE3PLW
• OE3RHA
• OE3WQR
• OE3WTW
• OE3WZA
• OE3ZK
• OE4EEA
• OE5ABI
• OE5AHT
• OE5BHO
• OE5EBO
• OE5ETL
• OE5FCL
• OE5GU
• OE5HYL
• OE5LHL
• OE5LTO
• OE5MDN
• OE5SKN
• OE5TU
• OE5WEM
• OE6ACG
• OE6DHE
• OE6DYD
• OE6FDD
• OE6GED
• OE6GWK
• OE6HMG
• OE6LMG
• OE6MRE
• OE6MXG
• OE6PKG
• OE6WDG
• OE6YCE
• OE7BMT
• OE7FFT
• OE7SNI
• OE7TTK
• OE7WWI
• OE7XHJ
• OE8CHR
• OE8ENO
• OE8ISK
• OE8JLQ
• OE8KQ
• OE8PZQ
• OE8RFK
• OE8STQ
• OE8VPG
• OE8WFQ
• OE8YLQ
• OE9HRH
• OE9RBV
• OE9VVV
• OE9XDV
• OE9XFA
• OE9XFR
• OE9XFU
• OE9XPT
• OE9XRV
• OE9XVI
• OE9XVV
• OE9XYI

Folgende 113 Rufzeichen wurden bewilligt:

• OE1ARX
• OE1CME
• OE1CSR
• OE1EAX
• OE1FPU
• OE1GXK
• OE1HYE
• OE1IAH
• OE1ICE
• OE1KDE
• OE1LON
• OE1MEX
• OE1MQM
• OE1MTM
• OE1RQH
• OE1SML
• OE2AHT
• OE2ASD
• OE2GBE
• OE2IOM
• OE2KRM
• OE2PAX
• OE2TST
• OE3BAH
• OE3BUZ
• OE3CLH
• OE3CPW
• OE3DMU
• OE3IFN
• OE3JQW
• OE3KAI
• OE3KIJ
• OE3LIX
• OE3MMO
• OE3ODF
• OE3PKG
• OE3PRA
• OE3SAD
• OE3XAV
• OE3XDI
• OE3XLL
• OE4AQB
• OE4CHZ
• OE4KSF
• OE4RUM
• OE4SPC
• OE4UCS
• OE5ANM
• OE5ANO
• OE5AOO
• OE5BGS
• OE5CML
• OE5EIR
• OE5GCK
• OE5GEV
• OE5HFR
• OE5HNG
• OE5IBL
• OE5ISK
• OE5ITH
• OE5KEK
• OE5KMF
• OE5KRE
• OE5LPE
• OE5MGE
• OE5NRF
• OE5OOA
• OE5RSE
• OE5SKE
• OE5SOE
• OE5TZR
• OE5WWV
• OE5XGR
• OE6AFQ
• OE6AFR
• OE6AGD
• OE6AOF
• OE6CWS
• OE6DWG
• OE6ERO
• OE6FWE
• OE6LTO
• OE6TTF
• OE6WGK
• OE7BOE
• OE7CGH
• OE7MOP
• OE7XTE
• OE8AAE
• OE8AAF
• OE8AAQ
• OE8ACD
• OE8ACF
• OE8ACQ
• OE8ADF
• OE8ADK
• OE8ADQ
• OE8AED
• OE8AEE
• OE8AEF
• OE8AER
• OE8AFE
• OE8AFF
• OE8FBF
• OE8HWK
• OE8IMK
• OE8KIM
• OE8MER
• OE8SRF
• OE8XAR
• OE8XBR
• OE9ALV
• OE9MON

Quelle: BMVIT

Dieser Eintrag wurde automatisch erstellt. Angaben ohne Gewähr.

Ich habe zwar angekündigt, den Baufortschritt zu dokumentieren, bin dann aber doch nicht so erpicht darauf gewesen. Eher kann ich also rückblickend und vom Fazit berichten, denn Berichte wie der von diesem OM z.B. sind weitaus detaillierter. Alles in allem lässt sich sagen, dass die Anleitung präzise auf alle Schritte eingeht; es ist hilfreich, alles ein- oder zweimal genau durchzulesen, bevor OM/YL mit dem ersten Arbeitsschritt beginnt. Anfangs musste ich auf die Definition von Begriffen achten, wie: Was ist ein Element (= 2 Strahlerhälften + 2 Abstandsseile + 1 Reflektor), ein Elementhalter (= „Dreizack“ auf den Spreizern), eine Universalklemme (= Verbindung von Drähten und Abstandseilen zu einem Element)? Sehr erfreulich war, dass das Tragrohr schon komplett fertig geliefert wurde, das hätte nochmal Zeit gekostet; das Tragrohr ist ein Koaxialfeeder, bestehend aus einem äußeren Rundrohr und einem inneren Vierkantrohr, die voneinander isoliert sind. Ein Ende aller Strahler ist elektrisch mit dem Außenrohr verbunden, das jeweils andere Ende symmetrisch dazu mit dem Innenrohr, und zwar anhand einer durchs Außenrohr durch führenden Schraube.

Das Tragrohr wird fertig geliefert. Höhe der Antenne (ohne Fiberglasstück) übrigens 102,5 cm – dieses Maß ist nirgends(!) angegeben.

Der Zusammenbau benötigt seine Zeit, hat aber Spaß gemacht und war ohne besondere Überraschungen. Ich habe dafür inkl. Feinabstimmung allerdings 19(!) Arbeitsstunden benötigt, aufgeteilt auf mehrere Bastelabende bzw. -wochenenden. So ging ich vor:

Als Fixierhilfe fürs Ablängen war mir der beigelegte Drahtrest zu kurz, ich habe ein Stück Wäscheleine verwendet.

Entgegen der Anleitung wollte ich die Schrauben nicht mit dem Hammer in die Verbinder der Spreizer hineintreiben, weil ich hierfür zu viel Kraft aufwenden hätte müssen und um das Material gefürchtet habe; die Öffnung war einfach zu eng. Ich habe sie stattdessen anhand einer Sicherungsmutter auf der Gegenseite schraubend hineingezogen. Selbiges dann beim Anbringen der innersten Spreizersegmente am Tragrohr: Das beschriebene „Eindrücken“ der Schrauben war mir schlicht nicht möglich.

Die Spreizer warten schon auf die Elemente...

... die schon fertig zusammengefügt sind.

Das Aufklipsen der Elementhalter auf die Fiberglasspreizer ging mit Hilfe einer Wasserpumpenzange ebenso ohne Kraftausdrücke, äh, -aufwand.