630 Meters Ground Wave Evaluation Network 630m GWEN

GM All, I will be calling CQ 474.0khz 9:30 local 0130z tomorrow for groundwave testing.

 

CQ 474.5 kHz CW from around 1330z to 1345z this morning... listening omni on main position, NE/SW loop on 2nd RX. I will likely get started a bit earlier but should definitely be QRV by 1330z

 

630m GWEN results this morning:
Participating 630m operators (per Slack #khz): W3TS CW 474.2, KB5NJD CW 474.5, AA8SH 474.0, K9KFR CW 474.2.
CW contacts: AA8SH K9KFR RST 339 229 251 mi.
Conditions were quiet.

 

This weekend I will call CQ 0930 local 1330z on 473.5khz. Last week K9KFR had a local birdie at 474.0 making copy difficult on that freq.

 

I plan to be QRV 474.5 kHz CW by 1330z but will probably start a few minutes early. I'll keep running until 1400z or so.. Ill listen omni on the main receiver and NE/SW on the 2nd receiver and will have the RBN SDR waterfall on a different omni for visual signal search.

 

Just heard my callsign coming back to me around 1321z.. someone was calling me. I marginally detect dits at times.. Please keep calling and I will keep looking with the rotatable antennas... Noise is high on the omnis.. If you are the signal in question, please let me know with a post.

 

630m GWEN results this morning:
Participating 630m operators (per Slack #khz): KB5NJD CW 474.5, W3TS CW 474.2, AA8SH CW 473.5, K9KFR CW 474.2, N9RU CW. WA3U listening.
Contacts: None
Conditions: Noisy QRN at K9KFR, Noisy QRN at N9RU, quiet at AA8SH.
Reports: AA8SH copied K9KFR 339 251 mi. WA3U copied W3TS 579 86mi. KB5NJD heard a calling station, callsign was in the noise.

 

QRV CW 474.5 kHz by 1330z until near 1400z. main op position omni, 2nd RX rotatable loop oriented NE/SW... Every bit of 5W EIRP on TX. Had a caller yesterday but never identified the signal. Very light signal on the recording and could only hear my call sign at the beginning. I suspect it is someone using one of the current transceivers that generate a low level signal directly into an antenna (no PA), possibly not resonated or matched. If so, that station is probably very local to me. If you are on again today, please send me a note and keep calling.. Its possible that we might squeak one out..

 

630m GWEN results this morning:
Participating 630m operators (per Slack #khz): W3TS CW 474.2, KB5NJD CW 474.5, N9RU CW 474.35, AA8SH CW 473.5, WA3U listening.
Contacts: None
Conditions: Quiet
Reports: WA3U copied W3TS 599 86mi.

 

HF OPS, please note the following signal report: "I was listening again this morning. Nearby W3TS was 599 on the west facing EWE, about 12db above the noise floor. On my 75M dipole at 50' he was 559, 6db above the noise. 73, Dave WA3U"

It bears repeating that W3TS is 86 miles from WA3U and can be heard 559 on a 75m dipole.

Please note the calls of the participating ops above. If you are within 100 miles of any of them, you may be able to copy on your existing HF wire, particularly if you run it as a Marconi. If you hear a station, please post your results here. ALL REPORTS MATTER. Thank you, Clark AA8SH.

 

I listened for you this past Sunday morning but didn't hear anything. I was just using a Icom 7600 with an 40 meter dipole. My 160 and 80 meter antennas are down at the moment. I have received other stations during the winter months on 630 meters as I like to listen to the non-directional beacons. Wish that I had the gear to transmit on this band!

Thanks, Greg W8NGA

 

Hi Greg,

Given that the 7600 is a quite new model in the grander scheme of things, you should evaluate it further to see if it will generate a low level signal that can be amplified. Many of the newer Icom's will do so and that signal can be amplified and filtered pretty easily. It helps if you are a builder. Plenty of schematics on the internet and most of them are relatively easy to put together.. see some of the other recent threads where this has been discussed.

The Icom manual likely will not show you any details for making this work on your transceiver. Manufacturers are notoriously bad about it, particularly if the bands were added "in the firmware" via an update... If you have a "Drive level out" you may be able to dial up 472 and see if there is a low level signal on that drive port. There may be a menu option to enable. You will just have to research it. Maybe someone using on of the other Icom transceivers that are known to work there can chime in with some comments or direction.

The point of all of this is that most of us are using modern gear. There is far more modern gear in use than boat anchors on 472 these days,

73 and good luck!

John KB5NJD..

 

Greg, thanks for the report. All reception reports matter, please keep them coming. Glad to know you are listening and planning. Please talk it up with anyone you know. You have at least four other 630m neighbors with whom you may be able to test 630 GW in the near future. Rick WB8JUI Belleview OH, Dan WB8DC Parma Heights OH, Ralph K8RYU Marietta OH, and Bob K9KFR Columbia City, IN. I can just work Ralph and Bob GW from Huntington, WV. My station isn't the greatest, needs work. My guess is you have a good chance of hearing Bob if he is on next weekend. Ralph has a 10w CW TX sitting around that he would pass on if you are interested. And you already heard from John KB5NJD above. If you have questions, John has answers. TNX and BCNU!

 

Good morning all. Clark asked me to share the results of a test that I performed yesterday.

Just days ago on Saturday, July 9, I posted that I had observed a caller during the Saturday morning ground wave session here in North Texas. The recording shows a few relatively clear dits of someone sending my call sign back to me but they seemed like they drifted out or stopped rather quickly. While mystery signals and carriers are common, these transmissions were absolutely legit.

I never received any email nor did I see any posts from the wouldbe 630m op. I wrote it off as possibly someone that heard me, wasn't expecting to hear me, quickly kludging something together that broke down rather rapidly, applying RF that whatever antenna might have been possible. Perhaps they were still in the 30 day UTC waiting period or perhaps they had not submitted notification at all and it was an attempt to not incriminate one's self. Pure speculation on my part.

Because of the proliferation of modern transceivers that are enabled to generate low level signals at 472 and 137 by way of firmware updates, I also considered the possibility that someone might have hooked their K3S or Kenwood 590SG or Icom XX up to whatever antenna they had available for HF, generating a few milliwatts and radiating far less EIRP. As I related to Clark, there are anecdotes of this being done in and around the NYC area several years ago with the band functioning as an intercom. As far as I know there have never been any sky wave reports of these signals and they are probably at the noise level for any usable distances.

With all that said I wanted to begin a series of tests where I couple my Kenwood 590 SG directly to the antenna, skipping the power amplifier altogether and apply just 1-5 mW to a very good antenna on 630 meters, resulting in tens or hundreds of microwatts EIRP. My antenna is an 80 foot tall asymmetric Marconi T with 100 foot and 200 foot long top loading wires and this sits over a little over 3 miles of radials (150 - 100 foot radials plus a dozen or more that are 200+ foot long and situated under the longer top loading wire). I had a few moments yesterday so I made a few calls on 474.5 kHz CW while listening on a few "local" webSDR's. This was a bit of a crapshoot because most of those online SDR's are not connected to good antennas for MF. On a couple, I could detect lines in the waterfall where I was transmitting but nothing was heard. Most of these were in the 40-50 mile range minimum and I knew that I was pushing it at these very low power levels on a noisy day. Also of note, the goto webSDR that I normally use for system evaluation located East of Dallas has not been online.

Next I contacted KE7A. Dick lives 30-40 miles to the Northwest of me as the crow flies and we have completed many ground wave QSO's over the years on 472....translation: Dick is a good base line to compare against since we have a lot of signal data between us. On a rather noisy day here in North Texas, Dick was unable to hear the low level CW signal while evaluating the band on multiple receivers and antennas. The next step was to run the test again with WSPR and see what the S/N really was (according to WSPR, anyway). A few tests showed that I was at -14 dB in a 2.4k bandwidth. That's not too shabby under the conditions and within the range that most CW ops will have a hard time copying without good, tight filters in place (Note: Dick had been listening with SSB filters when I was on CW. The result may have been different with DSP filters locked down which is how I typically work weak signals.)

For this first test, we left it at that and I think we will plan others going forward, particularly as we get into Fall and Winter and quieter overall conditions. I would also like to find and test with local stations that are closer to me using whatever antennas may be on site in hopes of narrowing down the practical possibilities of very low power operation on 472. The goal would be to evaluate concentric rings of stations in the local area.

Just a few days ago I posted a note directed at W8NGA about his Icom 7600. I had a chance to take a look at the manual and recalled a couple of comments from Icom users that successfully operated 472 with their Icom transceivers and apparently the low level RF comes right out of the selected SO239, not the drive level or xverter port. While the signal levels will be too low to evaluate on most watt meters, it may be possible to listen for yourself on a secondary receiver to see if a signal is being generated at 472. Similarly, the transceiver could be terminated into a dummy load and evaluated with a digital oscilloscope for frequency and amplitude. The other possibility is that this particular transceiver may simply not work on 472 but an email to the support people might possibly get a future firmware change to allow that. Since these transmitters are working like simple DDS's, they will likely work just find once they are unlocked. You won't know if you don't ask.

73!

John KB5NJD..

 

Right John, and thanks for the excellent and encouraging report! Your report suggests that many fellows likely have most of a 630m station in place already. A 630m capable rig and a dipole to run as Marconi needs only an output filter and matching coil to be on the air. For those considering it, here is the link to the required UTC registration. https://utc.org/plc-database-amateur-notification-process/ The required 30-day wait is just enough time to wind a coil and assemble a filter. GL and BCNU on 630m.