Messages

646

Equipment / Re: first land based SW Antenna?

« on: December 13, 2022, 1253 UTC »

Welcome to the community! :)

Since you mentioned an active loop, the MLA-30+ is an entry-level small loop antenna for casual medium- and short-wave listening.

It is definitely not a Wellbrook or W6LVP loop by any stretch of the imagination, but it would get you up and running for an under $50 investment. You would need a piece or two of PVC to support the loop, and a SMA to PL-259 to connect its coax to your FRG-7.

It uses USB for power. A decent USB phone charger like an Apple, Samsung, or similar wallwart you might already have should suffice. YMMV with RFI noise via cheap USB chargers. A small rechargeable USB power bank is another option.

The MLA-30+ does not have strong directivity with really deep nulls, so turn the loop to (hopefully) find the lowest noise floor if present, then set and forget. Enjoy listening, then decide if there is enough interest or even a need to consider a more elaborate antenna system.

647

10/11 meters / 11m Band Activity 13 DEC 2022

« on: December 13, 2022, 1049 UTC »

Airspy HF+D with 31' vertical at 10' elevation. I should get around to fixing the on-ground radials and rerouting the coax for my Shakespeare 318-GBT 18' vertical.

1045z - Very weak signal waterfall traces. Could be regional groundwave.
1050z - 27385l - Weak signal traces with intermittent modulation in the noise floor. Could be regional groundwave.
1101z - 27385l - Casual QSO. Regional groundwave.
1103z - 27225u - Casual QSO. Regional groundwave.
1107z - 22395l - Op calling another. Regional groundwave.

1123z - 22395l - UK op calling CQ DX.

1258z - 11m band open for DX. Numerous SSB frequencies. European DX noted.

1938z - Decent 11m band activity for a Tuesday afternoon. Screenshot below.

1956z - 27385l - Weird Al music QRM among the usual Ch38 DX traffic.

648

Equipment / Re: Best MWDX antenna?

« on: December 13, 2022, 0429 UTC »

Based upon my experience, you will likely do better with the Youloop and a preamp (if needed). At least it is a relatively balanced antenna, versus a miniwhip using the coax as a RF ground, so hopefully better SNR even if lower S levels.

I used to use a Youloop in a window as a backup indoor antenna during storms. Extra gain when needed was usually via a MFJ-1020B or a cheap eBay "+20dB" wideband preamp.


Estimated regional MUF is ~14MHz at 0958z. Numerous stations on the 19m band. Like 4-5 stations on the 16m band. Not too bad.

649

Equipment / Re: Best MWDX antenna?

« on: December 13, 2022, 0312 UTC »

Do you RF ground your indoor miniwhip? A ground wire even to an outlet ground might help. I have done it before in a pinch for a temporary setup. Huge YMMV depending upon electrical system RFI.

Could you hang it from an eve or gutter? Snake some RG-179 or RG-316 through the window. I have done that with the coax under the closed window in a piece of un-shrunk heatshrink tubing to get a feedline outside.

I often use those inexpensive eBay 75-ohm "flat" coax jumpers under windows. Most are not really flat, but more like probably RG-179 or similar inside the casing. They are typically less than 1' long, so losses are no big deal at HF and lower.


Since the 31' vertical feedpoint is readily accessible, I intend to replace the 1:1 balun with another unun to flatten the multi-band impedance curve at the feedpoint at little. Balancing losses at the feedpoint versus losses in the feedline. Yeah, I know is not a big deal for receiving, but I do not mind experimenting a little with the deployment during cooler weather.

I was considering another basic 4:1 unun, but I kept thinking about what G8JNJ did after analyzing the Comet CHA-250B match.

https://www.g8jnj.net/cometcha250b.htm

I considered building one, but then I stumbled across a similar dual-ferrite unun on eBay. :)

https://www.ebay.com/itm/303018040561

It is a little different design, but the same idea. I am not entirely sure how it will fare under 80m, but "whatever" as long as S is decently over N considering the usual noise levels down there anyway. Either way it probably will perform no worse than a simple 4:1 unun, so again, a "whatever" for my purposes. Something different to try I suppose.

At some point I might try the even simplier G8JNJ approach to multiband vertical matching using a bifilar winding on an iron powder core. It is further down the previously linked page. I still have an S9v18 vertical in storage.

650

Equipment / Re: Best MWDX antenna?

« on: December 12, 2022, 2225 UTC »

Sure enough. Before I have had a upper-HF vertical antenna using the guy lines with insulators as radials.

No insulators on the guys for this deployment. Using 14ga galvanized electric fence wire as guy wires since they are only lightly loaded with a 10' mast. The vertical lobe at low angles might not be ideal if modeled, but it is working okay enough (for now) for casual listening.

Better than the temporary 12' vertical on a tripod I am still using for the nightstand receiver. I am thinking possibly using an active miniwhip there.

651

10/11 meters / 12m Band Activity 12 DEC 2022

« on: December 12, 2022, 2155 UTC »

A few ops working 12m SSB at the moment. Airspy HF+D and 31' vertical here.

2150z- 24970u - Op in New Zealand working DX
2152z- 24980u - Casual QSO among NA ops including mobile op in NM

652

Equipment / Re: Best MWDX antenna?

« on: December 12, 2022, 2101 UTC »

The 31' vertical is back in business. It is dropped down to just ~10' of mast, that way the feedpoint can be serviced without having to take the mast and guys down.

The 4:1 unun probably has a broken connector or wire inside. Something to perhaps check later. I had an 1:1 in the parts bins, so I am using it for now.

Next up for twice the fun, despite earlier testing okay, the RG-11 appears to have a bad connector or similar. Figures. My coax stripper does not do RG-11, so just guesstimated it by hand with wire cutters. I have a stripper for RG-11 on order. I replaced the coax temporarily with a run of RG-6 I had already.

I removed the two 31' horizontal radials to simplify things. I just connected the balun ground to the mast and guys lines. Whatever, as it is just a receiving antenna anyway.

Did a NanoVNA sweep. SWR dips right above the 40m band and the third harmonic as expected. The cheap RG-6 has enough loss to somewhat smooth out the impedance from MW through 30MHz anyway. ;)

Net result? I doubt performance is much different than when ground mounted, but at least it gets the numerous 31' on-ground radials out of the yard.

I would have looked at the active antennas, but oddly enough, it seems I am out of RG-6 coax. ?!


Quickly skimmed 10m. A net in California, an op in Brazil working DX, and a few other signals. No preamp. Not bad IMO.

653

Equipment / Re: Best MWDX antenna?

« on: December 11, 2022, 0000 UTC »

We got the 31' vertical on about 21' of mast and the guys done.

Dropped a temp feedline to the house. Turned on the SDR, and normally strong signals are barely above the noise floor. Troubleshoot it tomorrow I guess.

So I am down to temporary vertical on a tripod in the yard for now.


Did a NanoVNA sweep at the base of the mast. The problem is somewhere up the mast. Either the feedline, which I checked earlier, or perhaps the unun that was previously working.

654

Equipment / Re: Best MWDX antenna?

« on: December 10, 2022, 1955 UTC »

Had help available today. :)

Nearly all of the old bulk RG-6 coax feedlines and on-ground radials are out of the yard. The 148' LoG built using RG-6 is still in the woods, so that might be a task for another day.

The 31' vertical is down and being prepped to be mast mounted. 4:1 unun, various clamps, mast guys, and two 31' radials are connected. The vertical antenna might get deployed today, though the two radials might just run down to the ground for tonight. I really could use a couple of eye bolts for the far ends of the radials, but I am not finding any large enough in the parts bins.

655

Equipment / Re: Beacon with a Raspberry Pi (rpitx)

« on: December 10, 2022, 1421 UTC »

The Pi can generate a square wave, and AFAIK, plenty of harmonics to go with that square wave.

You are likely going to want (and need IMO) a bandpass filter between the output and antenna.

I have no real idea of the output impedance at the Pi connection, but given the low power, I would not be too concerned about closely matching it. Given the few mWs of power contrasted against feedline and matching losses, I would look at placing the Pi and filter as close to or even right at the transmitting antenna feedpoint if possible.

656

10/11 meters / 11m Band Activity 5 DEC 2022

« on: December 07, 2022, 1901 UTC »

11m propogation is open for business here. American, Canadian, European, Mexican, etc. ops working DX on the upper side of 11m.

657

ID and Translation Requests / Re: 5626.800 UNID Peskies-What LANG? 12:30 UTC DEC 2 2022

« on: December 07, 2022, 1759 UTC »

SpeechBrain reported Chinese_Taiwan as a possibility, so potentially Taiwanese Mandarin, but admittedly the identification weighting did not return any real significant certainty. So a seriously huge YMMV here.

Chinese_Taiwan 0.027
English 0.027
Spanish 0.026
Chuvash 0.026
Tamil 0.025

Seems we can rule out English and Spanish. About the others, Chuvash favors Russia by population distribution. Tamil favors India, Sri Lanka, and Singapore.

https://huggingface.co/speechbrain/lang-id-commonlanguage_ecapa

658

Equipment / Re: Best MWDX antenna?

« on: December 05, 2022, 1310 UTC »

Might be a decent radio day here. Been listening to various regional 2m ops via my 31' vertical. o.0 Yeah I know, but it is the only working feedline routed to my Airspy HF+D right now.

659

10/11 meters / 11m+12m Bands Activity 5 DEC 2022

« on: December 05, 2022, 1154 UTC »

1153z - 27285am - overmodulated religious-sounding music about 1.5KHz high transmitting over other ops talking, among other assorted qrm
1157z - 27385lsb - usual regional morning traffic
1158z - 27520usb - Op in French Guiana working English and French language DX contacts
1206z - 27135am - North American DX
1210z - 27350usb - Caribbean DX?

Looking like DX might be decent today, but I have been dealing with a local splattering 11m this morning.

1217z - 27665usb - Sounds like Spanish language DX
1219z - 27928usb - French language DX
1226z - 27555usb - Usual DX hotspot activity. Think I caught an op in Venezuela among the mix.
1228z - 27545lsb - English language QSO about audio quality. Could be more like one op is off frequency.
1232z - 27025am - Usual Ch6 DX traffic
1234z - 27385lsb - Usual Ch38 DX traffic

Maybe the splatter is gone for awhile. Back to an -140dB waterfall.

1241z - 27770usb - Sounds like maybe faint SSTV modulation in the noise floor.

1242z - Multiple SSB frequencies active on the 12m band. North America, Italy, etc.

660

Propagation / Re: Solar Cycle Sunspot Number Progression

« on: December 05, 2022, 1105 UTC »

SSN is 93 at the moment. 2022 has only had one day so far with zero measured sunspots.

About the solar cycle, another marker is averaged monthly neutron counts, which have been trending downwards this year. Detected neutrons from cosmic rays are inverse to increased solar activity strengthening the sun's magnetosphere.

https://cosmicrays.oulu.fi/