Archive for the ‘review’ Category

New Book: Learning, Living, and Loving Morse Code…

There is a new book from a fellow Morse code amateur radio operator, Chris Rutkowski (NW6V), about “Learning, Living, and Loving Morse Code (in a Digital World).” NICE!

Title: “The CW Way of Life
link: https://amzn.to/3Tm3KfD

I received a new book! Here it is, at my radio shack operations desk, at NW7US radio station.

Already, I think it rivals any other book on the topic, including “The Art and Skill of…,” or, “The Zen of…”

It is not, however, meant to replace, but to augment, what is available. But, it is a complete guide, including a “work book” section (nearly half of the book?) on how to improve your skill. Really good stuff, but I’m only in one day.


73 de NW7US dit dit
https://nw7us.us

..

Solar Cycle 25, and a Life-Changing Event (Part 1 of 2)

From the RAIN HamCast episode #56, 2021-XII-11 (used with permission):

When you were knee high to a grasshopper, did you undergo a game-changing experience that shaped your future career?

Here is text from the introduction:

Tomas Hood/NW7US did. Tomas has been a shortwave enthusiast since 1973. He was first licensed as a ham in 1990 at age 25.

In the mid 1990s Tomas launched the first civilian space weather propagation website, HFRadio.org, which later spawned SunSpotWatch.com. His website, NW7US has been up and running since June, 1999. Tomas has contributed to the Space Weather Propagation column in CQ magazine for over 20 years, and for The Spectrum Monitor magazine since 2014.

A product of the Pacific northwest, Tomas resides today in Fayetteville, OH. RAIN’s Hap Holly/KC9RP spoke with Tomas recently about Solar Cycle 25 and the game-changing afternoon Tomas experienced in 1973 at age 8 ( Read more about this, at his amateur radio and space weather blog: https://blog.NW7US.us/ ).

Here is the first part of the two-part interview:

Mentioned in the interview is Skylab:

From Wikipedia’s article on Skylab: Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations included an orbital workshop, a solar observatory, Earth observation, and hundreds of experiments.

Tomas was drawn into space weather as a life-long passion, by inspiration from Skylab, and from the hourly propagation bulletin from the radio station WWV.

WATCH FOR THE NEXT EPISODE, PART TWO

This video is only part one. The RAIN HamCast will conclude Hap’s conversation with Tomas in RAIN HamCast #57, scheduled for posting Christmas Day.

Hap Holly, of the infamous RAIN Report (RAIN = Radio Amateur Information Network), is now producing The RAIN HamCast. The results are both on https://therainreport.com and on the RAIN HamCast YouTube channel, https://www.youtube.com/channel/UCUbNkaUvX_lt5IiDkS9aS4g

KEEP ON HAMMING!

The RAIN Hamcast is produced and edited by Hap Holly/KC9RP; this biweekly podcast is copyright 1985-2021 RAIN, All rights reserved. RAIN programming is formatted for Amateur Radio transmission and is made available under a Creative Commons license; downloading, sharing, posting and transmission of this ham radio program via Amateur Radio in its entirety are encouraged. Your support and feedback are welcome on https://therainreport.com. Thanks for YouTube Technical Assistance from Tom Shimizu/N9JDI.

 

New Antenna: The Following Footprints Are of My CW Signals (2021-March-14 @ 04:00 to 04:20 UTC).

The following footprints are of my CW signals on 2021-March-14 at about 04:00 to 04:20 UTC.

Click on this image to see a larger version of this image:
Footprint of NW7US Test CW Transmissions, Using New OCF Antenna

Location: EM89ad – Ohio
Antenna: OCD (Off-center Dipole)

Description of Antenna:

This is an off-center dipole, with the two legs running East-East-South (approximately 125 degrees of North), and West-West-North (about 306 degrees on the compass). The westward wire (leg) is approximately 107 feet in length, while the eastward leg is about 95 feet in length.

These legs (an off-center-fed dipole) is directly connected to about 90 feet of 450-ohm ladder line, which is hanging directly below, vertically, the feed point. The feed point is 50 feet above the ground.

The ladder line terminates (at the 12-feet-above-ground point) to a 4:1 current balun. This current balun then connects to a 100-foot LMR 50-ohm coax, which is running into the radio shack. It is connected via an antenna switch to my Icom IC-7610 transceiver. I am transmitting a 100-watt CW signal using an Icom IC-7610, in the following format:

TEST TEST TEST DE NW7US NW7US NW7US

The Reverse Beacon Network reports any spotting of this test transmission. The beta mapping interface, at http://beta.reversebeacon.net/main.php, then maps the resulting spots. To learn more about the RBN, visit http://beta.reversebeacon.net/index.php, or, http://reversebeacon.net/index.php.

I show the 20-, 30-, 40-, 60-, 80-, and 160-Meter band footprints.

I’ve been capturing these CW transmission spots, at different times of the day, today. I’ll get data from several days, at regular intervals, and create a overview of how the antenna appears to be working during this month and under these propagation conditions.

73 de NW7US dit dit

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One Aspect of Amateur Radio: Good Will Ambassadors to the World

This article is part two of the series taking a look at band plans and gentlemen agreements.
See part one, here: Land (er, FREQUENCY) Grab.  See part three, here: In Response — Can’t We All Just Get Along?

Displaced and Marginalized

There are some unhappy amateur radio operators in the world of shortwave operations. Users of Morse code, and digital modes other than the highly-popular modes engineered by Joe Taylor, K1JT, feel displaced on the many amateur radio bands where Joe’s wildly-popular mode FT8 has erupted.

Joe (born March 29, 1941), is a friend of hams everywhere, and is an American astrophysicist and Nobel Prize in Physics laureate (https://g.nw7us.us/2Ptquv1) for his discovery with Russell Alan Hulse of a “new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation.”

Many have asked questions like, “Did Joe Taylor K1JT Destroy Amateur Radio? Did Joe Taylor K1JT, Nobel Laureate and noted friend of hams everywhere, accidentally destroy amateur radio?” This question remains relevant, even as more and more FT8 operators take to the HF bands to chase wallpaper and awards.

FT8 Has Validity and Usefulness

Full disclosure: I administer a Facebook group for FT8 and FT8-related modes, because I believe that the mode has a valid place in our amateur radio technology portfolio.  Here is the Facebook group URL, if you would like to join the fun: https://www.facebook.com/groups/FT8.FT4.HF.6m/. Understand, I have used and will continue to use FT8.

Because it has a place, it stands to reason that everyone should become more aware of the impact of using FT8 on the bands. It also stands to reason that it should be used ethically, and in the best spirit of amateur radio.

Many amateur operators use the FT8 digital mode as a novelty when there isn’t much else happening on amateur radio shortwave bands. One of the great things about it is that you can tell when a band is open–even though you don’t hear any other signals of other modes on the band in question, you very well may hear the roar of FT8 on the band where propagation actually exists to somewhere else than your QTH.

Others use it to finally get their DXCC, or WAS, or other award and wallpaper. This is especially popular during this season of the sunspot cycle where there are no sunspots–propagation is limited to lower-HF amateur bands because there’s just not enough solar activity to energize the ionosphere enough to open up the higher segment of shortwave.

FT8 Has Limitations

Can FT8 be used for two-way conversations? No. However, the JS8CALL digital mode is designed from the FT8 mode, by changing the protocol in a way that allows free text. It is designed for ragchewing and the new version 2.0 offers three modes of chat with 50 Hz and 16 wpm, 80 Hz and 24 wpm, and the turbo mode at 160hz and 40wpm with turbo only having a 6-second turn around time. The designated frequency is 7.078, which many find much nicer to use.

However, many find JS8CALL combersome, and non-intuitive.  How fast and how reliably can it handle critical messages, say, during an emergency?  I’m sure the software will improve, but how good is the protocol?

A mode such as Olivia has been field proven, and time tested.  It can reliably handle traffic.

The Rant

During the early days of widespread FT8 operation that came with the first public non-Beta release of FT8-equipped WSJT-X software, I tried to reason with the FT8 development leadership team. I made a polite attempt at explaining how incredibly rude they were in purposefully programming into the software the default operating frequencies such as 7.075, 14.075, and so on.

One of the main leaders of that team slammed me and stated that “we only suggested those frequencies; the operator is free to change them.” Additionally, he stated that the team used a common QSO/Mode spotting website to see what digital modes or other operations (like CW) were sparser. They perceived that the frequencies they proposed where no longer active because they saw few if any spots. They thought that no one would care.

I explained that a single website-spotting strategy was illogical and very lazy. This is true for several reasons, at least.

I guess you have to have a Ph.D. to know better than any average ham who went by gentleman’s agreements. I have an extremely dim view of JT and his disciples. CW is not the only operating group he’s engineered out of traditional slices of spectrum. Olivia, and other modes, now have been pushed down into PSK subbands, and everyone is feeling the crowding. As far as my thinking of FT8, well, it is radio, but it doesn’t foster goodwill and building serious communications skill. IMHO.

Play Nice, Be Positive and Polite. Smile.

I’ve received wise counsel from a number of fellow amateur radio operators.  They implore us to not promote hostility between “us and them.”  That even though the WSJT team is playing the playground bully, we should not be vengeful, but polite and willing to negotiate in good faith.

If we don’t play nice with the bully then the bully won’t play with us.  And, the general public will side with the bully because the bully has the nice toys…

Good negotiations, though, take a willingness by both sides, so that conversation evolves,  resulting in positive, cooperative actions embraced by both parties. There are other amateur radio operators who have made attempts to open up talks with Joe and crew.  What are the results, so far?

We can hope that Joe Taylor and his group of developers and leadership take a proactive role and join a conversation that is with a wider group of amateurs than just the WSJT enthusiasts.  We hope that they will play fairly, and cooperatively, with the rest of the amateur radio community.

 

 

Tomas, NW7US

Tomas Hood, NW7US, is a regular contributor to AmateurRadio.com and writes from Nebraska, USA. Tomas is the Space Weather and Radio Propagation Contributing Editor to ‘CQ Amateur Radio Magazine’, and ‘The Spectrum Monitor’ magazine.

Yet in Quarantine, Life Blossoms!

About a month ago, I asked,

What is going on with you during this challenging situation?” and, “How do you use amateur radio, now that we are all stuck at home?  Are you using ham radio more, now?  Less?

I am moved to say, “Thank you, to each of you who commented and even those who made a video response. I sure appreciate it!

During that video blog (or, Vlog), back a month ago (link: Chat From a Quarantined Software Engineer – Welfare Check!), I mentioned my need for dental surgery. 

I did have to have the tooth removed.  It was completely split down the middle (top to bottom), down to the root.  There was no justifiable way to save the tooth. 

I now am missing two bottom back-most teeth, and one bottom, back-most tooth.  I can report that I have healed up nicely.  I am starting to enjoy a hamburger or two.

Through all of this, I’ve still been working. Also, I’ve been involved with a LOT more ham radio–especially with Morse code activities.

How has the last month treated you?  After watching this new video (below), please leave a comment or two, or three; let hear from you, okay?

More than anything, please leave a comment to let me know how you are doing.  I hope to hear from you.

Here’s the video:

73 de NW7US dit dit

 

From Lightning Comes a New Icom IC-7610 (First Transmission)

Wow. What a radio!

One of the most useful (and, to me, amazing) features of this Icom IC-7610, is the IP+ function, which, when turned on, improves the Intermodulation Distortion (IMD) quality by optimizing the direct sampling system performance. This function optimizes the Analog/Digital Converter(ADC) against distortion when you receive a strong input signal. It also improves the Third-order Intercept Point (IP3) while minimizing the reduction of the receiver sensitivity.

In short: I was listening to an s-0 (i.e., no strength-meter movement) weak signal of a DX station, when right adjacent to the frequency came an s-7 signal, wiping out my ability to copy that weak signal. I turned on the IP+ and the distortion of the adjacent signal disappeared, and once again, I heard the weak signal IN THE CLEAR! WOW!

This video is a quick capture of my running the Olivia Digital Mode on HF, on the 30-Meter band. The transmissions are of a two-way Olivia digital-mode radio conversation between station K8CJM and station NW7US on 12 November 2019 (UTC date). K8CJM is located in Dayton, Ohio, and I am located in Lincoln, Nebraska. I’m running the radio at full power. The radio is rated as being able to handle 100% duty cycle at full power. The radio ran cool, no significant heating.

A few months ago, a lightning strike took out my ham radio station. The antenna was NOT connected, but I did not unplug the power supply chain and my computer from the wall. The surge came in through the power mains, and fried my uninterruptable power supply, the interfaces between my PC and radio, and fried the radio. Thankfully, all of that was covered by my homeowner’s insurance policy, less the steep deductible. My insurance covered all of the blown items, and that provided me this chance to obtain a repack version of the Icom IC-7610. I bought an extended four-year warranty.

CAUTION: Check the documentation of your transceiver/transmitter. NEVER run your radio’s power out at a level that exceeds what it can handle in reference to the duty cycle of the mode you are using. Olivia, for instance, is a 100-percent duty cycle mode. Morse code is NOT quite 100% duty cycle. Nor is SSB, a mode that operates with a duty cycle much lower than 100%. Your radio’s manual should tell you the specifications regarding the duty cycle it can handle! If you run more power than your radio can handle with the given duty cycle of the mode in use, you will blow your radio’s finals or in some other way damage the radio! Beware! I’ve warned you!

Compression and ALC!?

Some have noted that it appears that I’ve left on the Compression of the transmitted audio. However, the truth is that compression was not being used (as is proof by carefully taking note of the zero meter movement of the Compression activity). I had the radio set for 20-Meter USB operation on the Sub VFO. Compression was set for standard USB operation. Note also that the radio was transmitting USB-D1, which means the first data/soundcard input to the radio.

Also, some people complain about my use of ALC, because, in their view, ALC (automatic level control) is a no-no for data modes.

The notion that one must NEVER use ALC when transmitting digital modes is not accurate.

Multi-frequency shift keyed (MFSK) modes with low symbol rate–such as the Olivia digital modes–use a single carrier of constant amplitude, which is stepped (between 4, 8, 16 or 32 tone frequencies respectively) in a constant phase manner. As a result, no unwanted sidebands are generated, and no special amplifier (including a transmitter’s final stage) linearity requirements are necessary.

Whether the use of ALC matters or not depends on the transmitted digital mode.

For example, FSK (Frequency-Shift Keying; i.e., RTTY) is a constant-amplitude mode (frequency shift only). In such a case, the use of ALC will NOT distort the signal waveform.

PSK31 does contain amplitude shifts, as an example, therefore you don’t want any ALC action that could result in distortion of the amplitude changes in the waveform.

On the other hand, the WSJT manual says that its output is a constant-amplitude signal, meaning that good linearity is not necessary. In that case, the use of ALC will NOT distort the transmitted signal-amplitude waveform. You can use ALC or not, as you choose when you run WSJT modes, or Olivia (MFSK).

Clarification

Nowhere in this am I advocating running your audio really high, thinking that the ALC will take care of it. I am not saying that. I am saying that some ALC is not going to be an issue. You MUST not overdrive any part of the audio chain going into the transmitter!

Transmit audio out of the sound card remains at a constant amplitude, so there will be no significant change in power output if you adjust your input into the radio so that the ALC just stops moving the meter, or, you can have some ALC meter movement. You can adjust your audio to the transmitter either way.

If the transmitter filters have a significant degree of ripple in the passband then you may find that RF power output changes with the selected frequency in the waterfall when there is no ALC action. Allowing some ALC action can permit the ALC to act as an automatic gain adjustment to keep the output power level as you change frequencies.

Linear and Non-Linear

Regarding linear and non-linear operation (amplifiers, final stages): While a Class-C amplifier circuit has far higher efficiency than a linear circuit, a Class-C amplifier is not linear and is only suitable for the amplification of constant-envelope signals. Such signals include FM, FSK, MFSK, and CW (Morse code).

If Joe Taylor’s various modes (in WSJT software) are constant-envelope signals, than class-C works, right? At least, in theory.

Some Additional Cool History

The digital mode, Thor, came out of DominoEX when FEC was added. Here is an interesting history of FSQ that seems to confirm that FSQ is like MFSK, so no problem with a bit of ALC.

The following is from https://www.qsl.net/zl1bpu/MFSK/FSQweb.htm

History – Let’s review the general history of Amateur MFSK modes. The first Amateur MFSK mode developed anywhere was MFSK16, specified by Murray Greenman ZL1BPU, then first developed and coded by Nino Porcino IZ8BLY in 1999. Before MFSK16 arrived, long-distance (DX) QSOs using digital modes were very unreliable: reliant, as they were, on RTTY and later PSK31. MFSK16 changed all that, using 16 tones and strong error correction. Great for long path DX, but nobody could ever say it was easy to use, never mind slick (quick and agile)!

Over the next few years, many MFSK modes appeared, in fact too many! Most of these were aimed at improving performance on bands with QRM. Most used very strong error correction, some types a poor match for MFSK, and these were very clumsy in QSO, because of long delays.

The next major development, aimed at easy QSOs with a slick turnaround, was DominoEX, designed by Murray Greenman ZL1BPU and coded by Con Wassilieff ZL2AFP, which was released in 2009. Rather than using error correction as a brute-force approach, DominoEX was based on sound research and achieved its performance through carefully crafted modulation techniques that required no error correction. The result was a simpler, easier to tune, easily identified mode with a fast turn-around.

DominoEX is widely used and available in many software packages. A later development by Patrick F6CTE and then Dave W1HKJ added FEC to this mode (THOR) but did not add greatly to performance, and at the same time eroded the fast turn-around. The final DominoEX- related development was EXChat, a version of DominoEX designed specifically for text-message style chatting. While completely compatible with DominoEx, it operates in ‘Sentence Mode’, sending each short over when the operator presses ENTER. EXChat was developed by Con ZL2AFP and released in 2014.

Back in 2013, Con ZL2AFP developed an MFSK mode for LF and MF which used an unusual decoding method pioneered by Alberto I2PHD: a ‘syncless’ decoder, which used a voting system to decide when one tone finished and another began. The first use of this idea was in JASON (2002), which proved to be very sensitive, but very slow, partly because it was based on the ASCII alphabet. The new mode, WSQ2 (Weak Signal QSO, 2 baud) combined the syncless decoder with more tones, 33 in total, and an alphabet specially developed by Murray ZL1BPU, which could send each lower case letter (and common punctuation) in just one symbol, resulting in a very sensitive (-30 dB SNR) mode with a 5 WPM typing speed.

In the subsequent discussion in late 2014, between the developers ZL2AFP and ZL1BPU, it was realized that if the computer had enough processing power to handle it, WSQ2 could be ‘sped up’ to become a useful HF chat mode. This required a large amount of development and retuning of the software to achieve adequate speed was involved, along with much ionospheric simulator and on-air testing used to select the most appropriate parameters.

Tests proved that the idea not only worked well, but it also had marked advantages over existing HF MFSK modes, even DominoEX. As expected, the new mode was found to have superior tolerance of signal timing variation, typically caused by multi-path reception, and would also receive with no change of settings over a wide range of signaling speeds.

So this is how FSQ came about. It uses the highly efficient WSQ character alphabet, IFK+ coding, the same number of tones as WSQ (33), but runs a whole lot faster, up to 60 WPM, and uses different tone spacing. The symbol rate (signaling speed) is modest (six tones per second or less), but each individual tone transmitted carries a surprising amount of information, resulting in a high text transmission speed. And it operates in ‘Chat’ (sentence) mode, which allows the user to type as fast as possible since they type only while receiving.

The ability to send messages and commands selectively has opened a huge array of communications possibilities.

What Makes FSQ Different

Incremental Keying – FSQ uses Offset Incremental Frequency Keying (IFK+), a type of differential Multi-Frequency Shift Keying (MFSK) with properties that make it moderately drift-proof and easy to tune. IFK+ also has excellent tolerance of multi-path reception.

IFK was developed by Steve Olney VK2XV. IFK+ (with code rotation) was proposed by Murray Greenman ZL1BPU and first used in DominoEX. IFK+ prevents repeated same tones without complex coding and provides improved rejection of propagation-related inter-symbol interference. In the context of sync-less decoding, the IFK+ code rotation also prevents repeated identical tones, which could not have been detected by this method.

Efficient Alphabet – In FSQ, a relatively high typing speed at a modest baud rate comes about because the alphabet coding is very efficient. All lower case letters and the most common punctuation can be sent in just one symbol and all other characters (the total alphabet contains 104 characters) in just two symbols. (The alphabet is listed below). This is a simple example of a Varicode, where it takes less time to send the more common characters. The character rate is close to six per second (60 WPM), the same as RTTY, but at only 1/8th of the baud rate. (RTTY has only one bit of information per symbol, 7.5 symbols per character, and wastes a third of its information on synchronization, and despite this, works poorly on HF).

No Sync – Another important factor in the design of FSQ is that no synchronizing process is required to locate and decode the received characters. Lack of sync means that reception is much less influenced by propagation timing changes that affect almost all other modes since timing is quite unimportant to FSQ; it almost completely eliminates impulse noise disruption, and it also contributes to very fast acquisition of the signal (decoding reliably within one symbol of the start of reception). Fast acquisition removes the need for the addition of extra idle characters at the start of transmission, and this leads to a very slick system. Add high resistance to QRM and QRN, thanks to the low baud rate, and you have a system so robust that it does not need error correction.

Cool.

See you on the bands!

Review – BTech DMR-6X2

by John ‘Miklor’  K3NXU

Several Dual Band DMR handhelds have been introduced into the market in the past few months. Having owned most of them, I would have to place this one toward the very top of the list. The DMR-6X2 is both VHF and UHF, Tier II  DMR digital as well as FM analog with most features geared strictly toward ham radio use.

Important Note:  The BTech DMR-6X2 is Not made by Baofeng. (see note below).  That being said, let’s see what’s…

In the Box
Included with the radio are the:
–  Two (2)  Li-Ion Batteries   (2100 and 3100 mAh)
–  Two (2)  Belt clips
–  Hand Strap
–  37 page User Guide – English
–  Charger base & AC adapter
–  Antenna – 6.25″ (16cm)
–  Programming Cable
–  Earphone / Microphone

General Description
–   DMR / FM
–   VHF / UHF Dual Band
–   Size:  5.1 x 2.4 x 1.5″   (129 x 61 x 39mm)
–   Weight:    9.9oz   (282g)  w/ant & 2100 mAh battery
–   Weight:   10.8oz  (306g)  w/ant & 3100 mAh battery
–   136-174   400-480 MHz
–   CTCSS/DCS  DTMF/2TONE/5TONE
–   Digital Simplex Repeater
–   <1.0w / 6.0w transmit
–   4000 channel
–   250 Zones (up to 250 channels per zone)
–   10,000 contacts
–   150,000 DMR Database Contacts
–   Part 90 compliant – 2AGND-DMR6X2
–   N0GSG Contact Manager Compatible

Basic Description  (additional features)
The heart of the 6X2 is the proven Anytone D868. Under contract with Anytone, BTech had several addition features exclusively added to the 6X2.

Some of the additional features exclusive to the 6X2 include:
–  Multiple Scan Groups
–  Priority Scan
–  Change TG via Keypad (Adhoc) with Unlimited Hold Timer
–  Display Color Options
–  Digital Simplex Repeater
–  Analog Squelch Level Adjustment
–  Start Up Code Plug Compatibility
–  Display Hold

– Multiple Scan Groups in Same Channel
The 6X2 allows multiple scan lists to be entered  per channel. You are no longer limited to one scan group entry per channel. The scan groups can include and mix of DMR or analog channels.

– Priority Scan
When developing a scan list, up to 2 channels can be assigned as priority. This allows the priority channels to be interwoven in the scan list. As an example:
–  Channel 1
–  Priority Channel 1
–  Channel 2
–  Priority Channel 1
–  Channel 3
–  Priority Channel 1

– Change Group via Keypad (“Unlimited” hold timer)
This is specially nice when using a hot spot. By setting a key function to “Dial” or “Long Press 0”, and the Group Call Hold time to “Unlimited”, you can enter a Talk Group using the number pad and it will remain permanently or until the channel is changed. No longer is the hold time set in seconds or minutes.

– Display Color Options
There are two display color options available. They are White on Black background, and Black on a Powder Blue background. (shown below). They are selectable by either software or keypad menu.

– Analog Squelch Level Adjust
The analog squelch level can now be adjusted using one of the programmable keys.

– Start up Code Plug
To assist with start up, the software was written to initially accept an Anytone D868 code plug.  I’ve had a 868 since they first came out, and this was a huge time saver. Everything transferred and I was ready to play radio in minutes.
Note: Due to the extra features in the code plug, a 6X2 CP cannot be transferred back to a D868.

– Digital Simplex Repeater
Not to be confused with a standard repeater, this feature allows the DMR-6X2 to function as a Store and Forward Simplex Repeater. The 6X2 records a transmission and stores it in memory. Immediately after the incoming signal is dropped, the transmitter keys and re-transmits the recorded audio. The re-transmission can be either on the same or different frequency (not necessarily on the same band).

This feature allows the 6X2 to be used as a relay point during events such as marathons, races, etc. where a central relay method is needed and there is no local repeater.

– Display Hold
When a signal is received, the data image (name, call, location, etc) remains on the screen until the next signal is received rather than drop back to a standby screen. There is a Call End indicator at the bottom, but the data remains.

The Technical Side of the 6X2


The
Transmitter

The frequency range of the DMR-6X2 is both VHF 136-174 and UHF 400-480 MHz. Along with DMR, the radio also supports analog FM (Wideband and Narrowband)

The power levels hold pretty close to the specifications. There are four power levels with a high of 5.0W and a Turbo mode of 6.5W. I personally run mine in 5W mode. Turbo isn’t going to Make or Break the signal, but it helps the battery.

What I do like is the low power mode is less than 1W. I run a hotspot here and if the power was only 0.3W I would be happy.

My audio reports have been excellent both through a DMR hotspot and the local repeaters. There is a five level microphone gain parameter that allows you to select the microphone gain level that best suited for your voice. I use level 3 (mid-level) for a full smooth audio response. I tried level 5 and found the audio was way too hot.

Power levels are listed below and were taken using a calibrated Bird Termaline wattmeter.

Enclosure
The DMR-6X2 case has a good solid feel and weight, and fits the hand well.  It weighs in at  9.9oz   (282g) with the standard battery attached and 10.8oz (306g) with the high capacity battery. Battery removal requires a simple push of the release slide located at the top of the battery. No battery sliding or pushing is required.

I found the keypad buttons a bit larger than most with a lighted keypad layout of three across and four down. This puts the zero (0) at the bottom of the keypad where I believe it belongs. The PTT button requires only a light pressure that doesn’t tire the finger to press.


Antenna
The included dual band antenna is 6.25″ which is a fairly common size for a handheld. I found that there was a slight improvement of about 2db by using an NA-771.  The 771 is 10″ longer, so a difference would be expected, but I’ll probably stay with the stock antenna.



Receiver and Audio
The receiver sensitivity is very good on both digital and analog. I found the receive audio is amazing with wide and smooth frequency range.

The volume control range is adjustable with the software. Level 1 sets the full range of the volume control to a soft level, even at full volume. Level 8 sets the volume range to very loud at the top end. My preference is level 3 to 5 which is plenty loud, even for mobile operation.

Display
The radio has a two multi-color display options. The high contrast White on Black, and the softer is a Powder Blue with multi-color icons. The color is selectable via software or as a keypad menu option. The screen size is 1.1″ x 1.4″ with excellent resolution .

There are multiple sites where the current DMR User Database can be downloaded. There are various formats available allowing you to view name, call, location, user ID, license class, etc.

.
Software
Along with entering data in the conventional manner, the software allows you to import and export data to ‘csv’ files. Loading in a contact (TG) list, channel list, database, etc. is relatively simple.

I found being able to export to a ‘csv’ file has several advantages. I like having my channel list in sequence. With most software, you can only add new channels to the bottom of the list. Now I can sequence the list so it’s easy to view then load it back into the code plug.

Adding a new repeater can be done in minutes. I just cut and paste a copy of an existing repeater, change the frequencies, and load it back.

Note: The BTECH 6X2 can import a code plug (.rdt) from an Anytone D868UV directly. This is a great way to get your 6X2 on the air. Once loaded, however, due to the expanded parameters, the D868 is not capable of reading a 6X2 code plug.


CSV transfer Caution
Adding large amounts of data, updating and re-sequencing via CSV files is a major plus, but should always be done with Caution. For instance, Talk Group data must always be loaded before or at the same time as the Channel data. If not, improper data attachment may not occur.

Always backup your current code plug before modification.

Firmware
As additional features and future enhancements are developed, the radio can be updated to latest model. A firmware upgrades can be done with a Windows computer in about 5 minutes.

Note: The DMR-6X2 firmware is specific to this radio. It cannot be uploaded to a different model in hopes of adding new features.

Programming Cable
The DMR-6X2 comes with the necessary programming cable. The UART chip inside the radio, so the cable itself is straight through. There is no circuitry inside the cable itself. The driver will load automatically when the cable is attached.

For reference, although the cable appears to be the same as some that have the chip in the cable, those cables are not compatible.

 

The charger base requires a standard 12vdc wall wart (included). The LED on the front of the charger base is Red when charging, and Green when either fully charged or no radio in the cradle. The battery easily charges to full capacity with an overnight charge.

Battery and Charger
There are two batteries included with the 6X2, a 2100mAh and a high capacity 3100mAh. With battery save on, I can get 2 to 3 days out of the 3100mAh battery before needing a charge.

There are also USB charging cables available with output of 12V. These can also be used in place of the included Wall Wart.

Conclusion
If you think the BTECH DMR-6X2 very closely resembles a D868UV, you are correct, but as shown above, it is definitely not simply a rebadged Anytone. There are features and enhancements that set these two radios apart. I think BTECH was wise to wait for the bugs to be ironed out before introducing the 6X2 to the market.

If you’re waiting for this radio to drop in price, don’t hold your breath. Its features and performance make it well worth the price.

The obvious pros are the following:

–  True Tier II DMR
–  Same Band and Cross Band digital simplex repeater
–  Dual Band VHF/UHF operation
–  Multiple Scan Groups per Channel
–  Priority Scan
–  On the Fly Talk Group Entry
–  Built-in Voice Recorder
–  2TONE and  5TONE decoding
–  150K user database capacity
–  FCC Part 90 certified for commercial use
–  N0GSG Contact Manager Compatible

There are plenty of options geared more for hams than commercial use. It performs well and makes a nice addition to the ham shack.

Available from:    and    Amazon


For Clarification
BTech (BaofengTech) is not a division of Baofeng. They are an ODM that partners with OEM manufacturers to spec and build to their own requirements, whether from scratch (UV-5X3) or from an existing product. This 6X2 is an Anytone at heart with additional unique features found only in that model.

 

 

 

Here’s a comparison chart showing the major differences.
Click to enlarge.


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