Many thanks to Pete (WB9FLW) who shares the following announcement from Sunil Lakhan (VU3SUA):
We have a new stock for easy bitx kits.
This kit is much improved and has no wiring.
The kit is very compact and portable too.
Check out in our store ..
Colors available . Black . Black with white panels . Blue with white panels .
Add a note for preferred color:
https://amateurradiokits.in
Thank you for the tip, Pete!
Many thanks to Pete (WB9FLW) who shares a reminder that the QSO Today Ham Radio Expo is this weekend.
I missed the last QSO Today Expo and heard that there were numerous technical glitches. Eric Guth (4Z1UG) has repeatedly described that experience as one of the most stressful in his life. He is making sure that this Expo will run smoothly by keeping all of the presentations and experience on the same platform. Eric is an amazing fellow and has gathered an outstanding group of speakers (over 90, I believe) and has made it so that if you can’t attend live, you can watch the presentations, on demand, for 30 days. Here are a few details from the QSO Today Virtual Ham Radio Expo site:
Click here to check out the presentation line-up and register early!
Many thanks to Pete (WB9FLW), who shares a link to this smartphone application-based digital mode called HF Pager:
(Source: NVIS Club)
By Evgeny Slodkevich, UA3AHM/OH5HM, and Dieter Kuckelkorn, DL1DBY
When going to an outdoor camping trip, we will find that in many parts of the world there is no cell phone service avail able in the back country. To make matters worse, in these areas there is almost never a VHF/UHF ham radio repeater in range when we need wide-area coverage. Apart from strictly local communications using VHF/UHF simplex radio, how do we send messages to friends and family over great distances? How do we call for help? A similar problem can even arise in an urban environment if a major disaster strikes like the break-down of the power grid.
In activities like back country trips in areas without cell phone coverage or in a widespread emergency with the loss of our normal means of communication we can use satellite phones, but this technology is very expensive, requires subscriptions and there is no guarantee that the complex infrastructure of satellite communications will work under all circumstances. The obvious solution for Ham Radio operators will be to switch to shortwave communication using battery operated radios and often NVIS modes of operation. NVIS stands for Near Vertikal Incidence Skywave, which means transmitting with special antennas straight up to communicate with other stations 30 km to 300 km (20 to 200 miles) away with low power – which would be the most useful communications distance if help is needed. We could use SSB voice communications, but this requires that the person we want to reach is sitting constantly at his or her radio to be able to receive the message. This can be a problem: In a real emergency we probably won’t have time for this. We could instead use capable digital modes with automatic message handling capabilities like JS8Call, but these require notebook computers or other complicated setups in the field which consume a lot of energy and can be difficult to recharge off-
grid on a reliable basis.
Evgeny UA3AHM/OH5HM and Sergej UA9OV have developed another mode of digital shortwave communications, which aims to be easy to use, capable and – most importantly – friendly to the operator’s resources. Apart from a low power battery operated transceiver and a small digital interface, only an Android smartphone is needed, which can be recharged with cheap and readily available consumer-grade solar chargers. Evgeny and Sergej have created an app called “HFpager” which allows to use the smartphone’s sound chip to encode and decode audio signals in the SSB audio passband of the transceiver – similar to PC based modes like FT8 and JS8Call. It uses rates of transmission of 1.46, 5.86, 23.44 and 46.88 Baud. Modulation is 18-tone Incremental Frequency Shift Keying (IFSK) with forward error correcting Reed-Solomon code RS(15,7) and a superblock by 4 RS blocks with interleaving.
Click here to continue reading the full article.
Click here to check out the HF Pager Android App.
Thank you for the tip, Pete!
Many thanks to Pete (WB9FLW) who writes:
Hi Thomas,
This years virtual FDIM presentations are now available on-line for those who missed it.
Click here to view Part 1 on YouTube.
Click here to view Part 2 on YouTube.
Enjoy!
Thank you for sharing this, Pete! Sadly, I was unable to attend live due to my schedule, so am very happy to see these excellent presentations. I do hope that things will be normal next year and FDIM will happen in person again. If you attend the Hamvention, I strongly encourage you to also take in FDIM–it is always an amazing event.
Many thanks to Pete (WB9FLW) who writes:
Morning Thomas,
Looks like our Prayers have been answer! 160 – 10, 5 Watts, single side band using a new transmitting technique , no more DSB!
All for 80 bucks (includes 3 band modules)
The v. III version debuts a novel firmware scheme for our Si5351A/MS5351M VFO which allows a move away from DSB transmission to SSB, by a new process we are calling AFP-FSK (Audio Frequency Processed-FSK).
What’s not to like 🙂
Pete WB9FLW
Brilliant, Pete! This looks like a fun kit to build and certainly an affordable way to hit the digi modes! Thank you for sharing!
Many thanks to Pete (WB9FLW) who shares the following article by Bob (KD8CGH) regarding the uSDX transceiver kit.
I reached out to Bob who has kindly given me permission to share his article on QRPer:
by Bob Benedict (KD8CGH)
There is a new open source, home brew multi band, multi mode QRP transceiver that grew out of the QRP Labs QCX. Through some serious wizardry it retains an efficient class E RF amplifier for SSB and digital modes. It crams impressive SDR capabilities into an Arduino.
This has an interesting international development process conducted on https://groups.io/g/ucx/topics with contributions by many, including the usual gang of suspects: Hans Summers G0UPL, Guido Ten Dolle PE1NN, Barbaros Asuroglu WB2CBA , Manuel Klaerig DL2MAN, Kees Talen K5BCQ, Allison Parent KB1GMX, Jean-Marie T’Jaeckx ON7EN, Ashhar Farhan VU2ESE, and Miguel Angelo Bartie PY2OHH. I apologize to the many others whose names I didn’t list. A summary is in the WIKI https://groups.io/g/ucx/wiki.
The basic work uSDX appears to have been accomplished by Guido Ten Dolle PE1NNZ. It uses pulse width modulation of the PA supply voltage to transmit modes other than CW while retaining class E efficiency and uses a direct conversion SDR receiver.
The basic idea behind Class E nonlinear amplifiers is that transistors have little loss when they are switched fully on or off. The losses occur when devices are limiting power flow in linear amplifiers. The idea behind a Class E amplifier is to use transistors in a switching mode to generate a square wave to drive a resonant circuit to generate RF power.
This method is used in the popular QCX QRP CW transceiver kit line developed by Hans Summers and sold through QRP Labs https://qrp-labs.com/. More than 10,000 of these great transceiver kits have been sold (I built one). There is a good discussion of the circuit and particularly of the class E amplifier in the excellent QCX documentation https://www.qrp-labs.com/images/qcx/assembly_A4-Rev-5e.pdf.
The QCX was the base for the QCX-SSB which starts with a QCX and modified the circuit and software to add SSB capabilities. The wizardry that Guido accomplished uses pulse width modulation of the PA supply voltage to control the amplifier in an Envelope Elimination and Restoration (EER) technique https://core.ac.uk/download/pdf/148657773.pdf. To generate SSB a DSP algorithm samples the audio input and performs a Hilbert transformation to determine the phase and amplitude of the complex signal. The phase changes are transformed into temporary frequency changes which are sent to the clock generator. This result in phase changes on the SSB carrier signal and delivers a SSB-signal with the opposite side-band components is attenuated.
On the receive side a direct conversion SDR receiver is used with the I and Q signal digitized and all further processing carrying out digitally. Attenuators are included to help not overload the ADC range. Documentation is at https://github.com/threeme3/QCX-SSB . In addition to a good description of the theory and hardware mod there is also a good description of the software command menu.
From there development took off in several directions. One is by Barbaros Asuroglu WB2CBA and Antrak that uses through hole components (mostly) and replaceable band boards that hold the low pass filter and band dependent class E amplifier components (an inductor and capacitor). Barb also includes boards designed to be a case top and bottom, battery pack and a PA.
Another development track by Manuel Klaerig DL2MAN uses SMT components in a stacked board layout and has a relay switched band pass board https://groups.io/g/ucx/message/1596 and https://groups.io/g/ucx/files/DL2MAN uSDX-Sandwich Files. A new revision has been released that uses serial resonance class E amp design and easier to obtain relays, https://groups.io/g/ucx/files/DL2MAN uSDX-Sandwich Files with new Serial Resonance Class E Multiband Circuit .
Other development streams include one by Kees Talen K5BCQ https://groups.io/g/ucx/files/K5BCQ uSDX Board Schematics and Jean-Marie T’Jaeckx ON7EN https://groups.io/g/ucx/files/QCXV4.zip.
I built the variant designed by Barbaros Asuroglu WB2CBA and I’m pleased with it’s performance. I ordered 10 main boards and 40 LP filter band boards PCBs from PCBWAY, but now you can also purchase single boards sets from https://shop.offline.systems/.
I also designed and 3D printed a case for the transceiver and a small box to carry band boards. Info at https://www.thingiverse.com/thing:4582865 and at https://www.thingiverse.com/thing:4587868 and also in the files section https://groups.io/g/ucx/files/3D printed case for Barb WB2CBA V1.02.
In an example of hams collaborating at its finest, Hans Summers announced on 9/11/2020 that his new QCX mini product, a QCX in a smaller package, will include a daughter board that can be used to give the QCX mini a uSDX like SSB capability. The QCX mini has the same circuit as the QCX but uses SMD components packaged it into a two board stack that is less than half the volume of the original QCX. The mod is unsupported by QRP-LABS but may be supported by the uSDX group.
http://qrp-labs.com/qcxmini.html
More information at https://groups.io/g/ucx/topics and don’t forget the WIKI https://groups.io/g/ucx/wiki.
73
Bob, KD8CGH
Many thanks again, Bob, for sharing this excellent uSDX introduction. Thanks again for the tip, Pete!
Pete also notes that there is a very active uSDX experimenters discussion group on Groups.io with over 100 members: https://groups.io/g/ucx
Many thanks to Pete (WB9FLW), who writes:
Found this link on the Soldersmoke Blog this morning.
Interesting to compare this 70 year old Rig with your KX2 or KX3!
We’ve come a long way since then.
Indeed we have, Pete! But, man oh man! What a gorgeous vintage portable–absolutely beautiful vintage example of form following function!
Many thanks to QRPer, Pete (WB9FLW), who writes:
Get it while you can (Classic Edition) includes CD-ROM PDF Files for Solid State Design and Introduction to RF Design.
Closeout Price $20!
Very sad to see this go,even if you own a copy buy a spare!
Click here to order your copy at the ARRL.
Thank you for the tip, Pete!
Many thanks to Pete (WB9FLW) who writes:
Hi Thomas,
QRP Labs has just announced the QCX+ which as the name implies is an upgraded version of the very popular QCX line of transceivers
To date almost 10,000 kits have been sold, here’s a brief overview of the the differences and new features made to this popular Transceiver.
The QCX+ is the almost same circuit as the QCX, with two very minor changes. QCX+ runs the same firmware as QCX, and has identical operational and performance characteristics. QCX/QCX+ firmware will always be compatible with both the QCX and QCX+. The evolution of QCX to QCX+ provides several improved features in physical layout, as follows:
1) Physical layout of controls and connectors
2) Optional enclosure
3) Additional and changed connectors
4) More spacious PCB, more than double the board area, with less densely packed components, and more test/modification points
5) Improved heatsinking
6) Three minor circuit changes
7) No microswitch key
Price has gone up slightly to $55, still no other QRP Transceiver on the market today comes close to the features offered by the QCX+ at this price point.
More Info:
Thank you so much Pete! You’re an enabler! Since I’m not at Hamvention right now, those radio bucks are burning a hole in my pocket. The QCX+ looks like a fun transceiver to build! Thanks for the tip.
Many thanks to QRPer, Pete (WB9FLW), who shares the following sneak peek video of the new IC-705 transceiver from Amateur Logic TV with guest Ray Novak from Icom America:
Pete also notes that Ham Radio Outlet’s price has been announced a the 2020 Orlando Hamcation. According to two members of the group, the pre-order price at Hamcation is $1,175 US–the price will increase $100 after Hamcation.
Availability is still unknown: retailers and Icom have not committed to firm delivery date yet other than noting it will be sometime in 2020.
Thanks, again, Pete for the tip!