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As much as I love CW and try and promote its use on 630m, one cannot deny the growing interest and use of the WSPR mode on our newest ham band.



Its ability to dig deep into the noise and successfully decode signals as weak as -30db makes it an attractive method of watching the night-to-night and hour-to-hour propagation magic.

One only needs to check the number of stations logged into the WSPRnet Activity-page, uploading 630m spots each night ... a typical evening will see 60-80 calls listed.

The main problem with WSPR is that it's a one-way, beacon-only mode and it's not possible to utilize it for a valid two-way contact. It's nice to know that station 'A' is able to hear station 'B', and vice-versa, but the only way for both stations to know this is for them to both be monitoring the internet uploads ... if both stations were able to confirm their respective receptions all via radio, then a two-way contact could be claimed. Thankfully, there is another mode that solves this dilemma, without internet intervention and that's JT9.

JT9, developed by K1JT, is a spin off from his JT65 weak signal QSO-mode software developed for EME. JT9 has been tailored for the noisier HF and MF bands and is apparently, about 2db more sensitive than JT65. In the past, I have made several single-yagi EME contacts on 2m using JT65, with many of these QSO's being in the -27 to -29 db range. This would suggest that 630m JT9 contacts could be made at signal levels as weak as -30db!

A recent "630m Activity Weekend" in Europe turned out be a "630m JT9 QSO Party" with dozens of Europeans working each other throughout the event using this weak signal mode with great success. It looks very much as if JT9 may now be the go-to mode for two-way work on 630m when, as is often the case, signals can be easily seen on a visual waterfall display, but are too weak to be heard on CW.

DC1RJJ's 630m JT9 action courtesy: KB5NJD

On this side of the Atlantic, recent JT9 contacts have been made between several of the U.S. experimental stations. WH2XCR in Hawaii (K9FD/KH6) and WG2XIQ in Texas (KB5NJD) worked on Dec 9th, while WH2XGP (W7IUV), WG2XSV (W0YSE/7) and others have been exploiting the power of JT9 to work around the country.

Such has been the case for me recently, with the arrival of VE3OT on 630m. Since beginning his nightly slow speed CW, QRSS6 beaconing, his signals have been easily visible here every night but only strong enough to hear aurally, on two occasions.  It is likely that we could work each other fairly routinely on JT9 but will need to wait for very good conditions to work on CW.

The good thing about modes such as WSPR and JT9 is that they can be used without the need for linear amplifiers in the PA ... class D or E amplifiers, fairly universal in the LF/MF world, can be employed. The most popular route at present seems to be via a homebrew  transverter that will allow the use of the station's main HF transceiver (using the tone-generating JT9 / WSPR software) to generate the required 630m RF.

I've been looking for a new radio workbench project to catch my interest and building a 630m transmitting converter is beginning to look more attractive, now that we have another DX target in VE3 land ... of course, if and when the U.S.A. gets the band, there will be an entire new crew of stations spread across the continent to keep the transverter busy!


Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

It looks like my tri-band Par antenna, which should be a good match on 10m, 20m and 40m is faulty.  It is a good match on 10m, but only on 20m and 40m via the ATU. Tomorrow I shall try loading it up as a long wire tuned against ground via the ATU. Somewhere I have a Sandpiper Poliakov vertical that I should erect. As I recall  this has a 9:1 unun so it matches well on most HF bands via an ATU.

Even soldering on a coax is hard work these days! Oh to be fit.

At the moment I am on 630m WSPR using the earth-electrode “antenna”.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

On 7. November 2015, several radio amateurs in northern California heard echoes in the 80 meter band. I was made aware of it by Jack, W6FB in Santa Clara, who recorded signals from K6YT some 25 miles away. According to W6FB, the echo effect was also heard north of Sonoma (several hundred miles north of him, reported by N6ZFO).

KM6I, Gordon, in Palo Alto also heard echoes of his own signals and recorded them. In his blog he analyzed the delay from the output of his transceiver and found 157 ms. He found that to be so close to the round-the-world time for signals of 138 ms, that he assumed that to be the cause.

I don’t agree, so I took the location of W6FB at locator CM97ah (Santa Clara) as a starting point for computing delay. This is latitude 37.31 and longitude -121.96 and gives a geomagnetic latitude of about 42.5 degrees. Then I put it into my program for computing path length along geomagnetic field lines assuming a height of the reflecting ionosphere on the opposite side of 100 km. The result is shown in the figure and predicts a delay time of 126 ms. My estimate of uncertainty is +/-5 ms.

The delay value is slightly less than 138 ms and easy to confuse with a round-the-world path. The challenge with estimating delays like this from the signal is that amateur transceivers may have an unspecified delay between start of transmission and start of sidetone. Measuring on the audio output as done here, measures the sidetone, not the actual RF.

I discussed this source of error in my 2009 QST article “Magnetospheric ducting as an explanation for delayed 3.5 MHz signals.” Therefore the measurement shown above may fit with 138 ms just as well as with 126 ms, it depends on the actual transceiver’s delay.

Other properties of the echo, such as the amplitude of the echo which according to W6FB at times was louder than the direct signal, also point to the duct theory as the explanation.

Others have heard such echoes also:

• 165-168 ms, K4MOG, February 2006, 80 m. Listen to the signal here. This event is also the object of the analysis in my QST article referenced above.
• 210-220 ms, G3PLX, November 2006, 160 m. Listen to the signal here.
• 214-219 ms, W2PA, February 2008, 80 m.
• 237 ms, OZ4UN, January 2009, 80m, Listen to audio file where also OZ7BQ very close by heard the echoes.
• About 200 ms, G3ZRJ, January 2012, 80m. Also heard by GW3OQK, 100 km apart.

Other posts on the theme: Magnetospherically Ducted Echoes or Medium Delayed Echoes

Sverre Holm, LA3ZA, is a regular contributor to AmateurRadio.com and writes from Norway. Contact him at [email protected].

On 7. November 2015, several radio amateurs in northern California heard echoes in the 80 meter band. I was made aware of it by Jack, W6FB in Santa Clara, who recorded signals from K6YT some 25 miles away. According to W6FB, the echo effect was also heard north of Sonoma (several hundred miles north of him, reported by N6ZFO).

KM6I, Gordon, in Palo Alto also heard echoes of his own signals and recorded them. In his blog he analyzed the delay from the output of his transceiver and found 157 ms. He found that to be so close to the round-the-world time for signals of 138 ms, that he assumed that to be the cause.

I don’t agree, so I took the location of W6FB at locator CM97ah (Santa Clara) as a starting point for computing delay. This is latitude 37.31 and longitude -121.96 and gives a geomagnetic latitude of about 42.5 degrees. Then I put it into my program for computing path length along geomagnetic field lines assuming a height of the reflecting ionosphere on the opposite side of 100 km. The result is shown in the figure and predicts a delay time of 126 ms. My estimate of uncertainty is +/-5 ms.

The delay value is slightly less than 138 ms and easy to confuse with a round-the-world path. The challenge with estimating delays like this from the signal is that amateur transceivers may have an unspecified delay between start of transmission and start of sidetone. Measuring on the audio output as done here, measures the sidetone, not the actual RF.

I discussed this source of error in my 2009 QST article “Magnetospheric ducting as an explanation for delayed 3.5 MHz signals.” Therefore the measurement shown above may fit with 138 ms just as well as with 126 ms, it depends on the actual transceiver’s delay.

Other properties of the echo such as the amplitude of the echo which according to W6FB at times was louder than the direct signal. This points to the duct theory as the explanation.

Others have heard such echoes also:

• 210-220 ms, G3PLX, November 2006, 160 m. Listen to the signal here.
• 165-168 ms, K4MOG, February 2006, 80 m. Listen to the signal here.
• 214-219 ms, W2PA, February 2008, 80 m.
• 237 ms, OZ4UN, January 2009, 80m, Listen to audio file where also OZ7BQ very close by heard the echoes.

Other posts on the theme: Magnetospherically Ducted Echoes or Medium Delayed Echoes

Sverre Holm, LA3ZA, is a regular contributor to AmateurRadio.com and writes from Norway. Contact him at [email protected].

Following my last post it is perhaps ironic that for the last few evenings I have been plagued by an increase in QRM.

Trying some JT65 on 40m I was being plagued by S8-S9 of local noise, it is noise I have had regularly (even before the purchase of my PLT devices) so I reconnected up the WiMo QRM Eliminator, which has been collecting dust, to see if I could improve matters.

Using just a short piece of wire as the auxillary 'noise' antenna managed to null out most of it to greatly improve reception. No commentary on the video below but hopefully you can see it working.


Interestingly the noise seems to abate around 11pm when people are off to bed.
Andrew Garratt, MØNRD, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].

Following my last post it is perhaps ironic that for the last few evenings I have been plagued by an increase in QRM.

Trying some JT65 on 40m I was being plagued by S8-S9 of local noise, it is noise I have had regularly (even before the purchase of my PLT devices) so I reconnected up the WiMo QRM Eliminator, which has been collecting dust, to see if I could improve matters.

Using just a short piece of wire as the auxillary 'noise' antenna managed to null out most of it to greatly improve reception. No commentary on the video below but hopefully you can see it working.


Interestingly the noise seems to abate around 11pm when people are off to bed.
Andrew Garratt, MØNRD, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].

Sunday, January 10, 2016 at Briarcliffe College in Bethpage, NY

• D-Star and System Fusion
  Randy Gutentag WA2RMZ and Scott Weis KB2EAR
• DMR (Digital Mobile Radio)
  Bernie Hunt K2YO
• SDR (Software Defined Radios)
  Neil Goldstein W2NDG
• Keynote Address
  ARRL Chief Executive Officer Dave Sumner K1ZZ
• Building Your First Ham Station
  Phil Lewis N2MUN
• Basics of HF Operating
  Phil Lewis N2MUN and Mel Granick KS2G

Matt Thomas, W1MST, is the managing editor of AmateurRadio.com. Contact him at [email protected].