HFU HF Underground
General Category => General Radio Discussion => Topic started by: redhat on December 16, 2018, 2231 UTC
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I'm curious for feedback from listeners last night as to the suitability of 4085 as a transmission frequency. One of the problems that plagues 43 meters is a combination of peskies and wideband data modes, both seem to be absent on 73 meters. The down side to this frequency range is that it resides in maritime frequency allocations, and there does seem to be some data activity, albeit bursty.
With the downturn in propagation (SSN last night was ZERO) and the tendency for 43 meters to go long very early, I see few other choices but to head for longer wavelengths. Halloween this year made this problem crystal clear for me, and until propagation returns to peak level or the noise becomes excessive on lower frequencies to allow enjoyment of a program, I see little reason to return to 43.
Any thoughts, or perhaps other ranges we should explore? I would prefer not going much lower, as antenna considerations become a problem.
+-RH
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I can't speak for the potential problems with licensed users of this territory, but over the past two months, I've tuned here from time. I haven't heard any peskies or MARS ops, so that seems like a big plus. I also haven't heard much of the data that turns up on 43m. Strictly from the perspective of a listener, it seems like this is a great place to broadcast at night from the late fall through early spring.
I also wonder if there are any open chunks of spectrum around 60m, now that a lot of tropical band stations are dark
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As Andrew stated, 4085 is probably the clearest frequency in the 73 meter range.
And, a frequency up around 60 meters, or perhaps around 5190 might offer some advantages as well.
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With the demise of USN/MC MARS who used to hold this frequency, I think the closest MARS freq is still 4041, in use by USAF or Army MARS today. It'd also be neat to hear piracy on the region 2 to 2.5MHz hint hint.
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With the demise of USN/MC MARS who used to hold this frequency, I think the closest MARS freq is still 4041, in use by USAF or Army MARS today. It'd also be neat to hear piracy on the region 2 to 2.5MHz hint hint.
Would you like to volunteer to help erect a 75' antenna every weekend? hint hint... ;D
+-RH
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I'm thinking 5060 - 5070 ?? I can tune to 5 Mhz I'm not able to tune 4085 at this time I'd have to put up another antenna.
tAC
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70 meters shows some great promise with prior experience on several frequencies in the 4000-4100 kHz range. As for 2000-2500 kHz, that might be possible. 3375 kHz is another good one. 3400-3500 kHz is an aircraft band so I would avoid operating there.
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I heard no interference issues anywhere around 4085 kHz that night.
Propagation wasn't great in my area; Radio Verdad down on 4055, which I use to judge reception on that band, was very weak that night compared to usual. But during periods when the fading settled down, you sounded great. To echo some of the others here, though, it might be interesting to try something between 5050-5100 kHz.
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The 5 MHz region is possible. Currently 50' seems to be the limit for a self supporting vertical in most weather conditions, and that would be 1/4 wave at 5 MHz or so. I'm open to ideas, although I would have to build a new LPF, antenna matching network, and tank coil for any new frequency, along with a new set of radials.
Good stuff!
+-RH
P.S. how about 5110? It looks to have enough room for 10KHz audio.
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5 MHz seems to be closer to the performance of 6 Mhz with 4 Mhz performing better at night. If would be interesting to see how well you will do in the 5100 area +- Your could try 4800 +- area also on the low side of the broadcast band if it is clear of stations. The advantage in going higher is a lower noise floor with propagation a little less at night.
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I'll present my views as a listener: At the risk of stating the obvious... It's far far more likely for a station to be heard if it is transmitting where people are listening. This includes people tuning the dial, as well as those of us that run nightly SDR recordings.
If an op lets me know they'll be on random frequency XYZ on a given evening, I can set up my SDR recording to catch them. But otherwise, I'm probably going to miss them, as will most other listeners. This is the current "problem", if you will. Please don't take this as criticism, I appreciate the efforts ops make and enjoy listening to any broadcasts I happen to be able to catch.
If on the other hand a particular band has a fair amount of activity (as 43 meters does now), I'm more likely to be recording and catch it, as will others. I understand there's technical issues involved, with resonant antennas, transmitter frequency ranges, and so on. Some coordination amongst operators (which seems to be the intent of this discussion, yay!) to pick one additional band (say 100 kHz wide) on top of 43 meters, vs everyone using their own band, is going to result in a lot more folks hearing the transmissions. Just saying 8)
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Chris makes a good point. I have had excellent results with 4 MHz / 70 meters, although I haven't tried 5 MHz / 60 meters and I understand the issue re: building verticals for lower frequencies...maybe 6800-7000 kHz and 4000-4100 kHz?
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I'll present my views as a listener: At the risk of stating the obvious... It's far far more likely for a station to be heard if it is transmitting where people are listening. This includes people tuning the dial, as well as those of us that run nightly SDR recordings.
If an op lets me know they'll be on random frequency XYZ on a given evening, I can set up my SDR recording to catch them. But otherwise, I'm probably going to miss them, as will most other listeners. This is the current "problem", if you will. Please don't take this as criticism, I appreciate the efforts ops make and enjoy listening to any broadcasts I happen to be able to catch.
If on the other hand a particular band has a fair amount of activity (as 43 meters does now), I'm more likely to be recording and catch it, as will others. I understand there's technical issues involved, with resonant antennas, transmitter frequency ranges, and so on. Some coordination amongst operators (which seems to be the intent of this discussion, yay!) to pick one additional band (say 100 kHz wide) on top of 43 meters, vs everyone using their own band, is going to result in a lot more folks hearing the transmissions. Just saying 8)
Thanks to the HFU, once someone spots the signal and posts it, many more people find out about it who otherwise may miss it. Through selective announcements, it is less likely that a signal would go unnoticed, for better or worse. I did receive a few emails the other night from folks who stumbled across the show while looking for something to listen to. Being adjacent to ham bands can help in this regard, but can also be a problem for obvious reasons.
+-RH
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A 1/4w vert for 5MHz would get you some lovely dx I bet.
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Yes, at the expense of local coverage.
+-RH
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Over this way I note some Asian CW and voice traffic in the block 4.000 to 4.100MHz with some of the CW traffic being Chinese military. There is also a Philippines station active on 4.090MHz USB from time to time speaking in broken English and Tagalog.
Quite appears to be "empty/unused" on one side of the world can be the opposite elsewhere. 8)
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My opinion: we have it so easy these days to get the word out about a broadcast on a new/unusual frequency so that others can tune in almost instantly. HFU forum log posts, as well as the very excellent HFU Rocket Chat system (which hopefully everyone here is using!) plus the fantastic capability for SDRs to 'spot' signals where radios with knobs aren't looking.
I remember in the 90s there being quite a sense of crisis when the old favorite pirate frequency of 7415 became crowded by strong SWBC stations and then eventually WBCQ took the frequency. Where would pirates go, and how would listeners find them? Maybe some enterprising DXer would be spinning the knobs enough to stumble over a new frequency, and report it to the A*C*E, where other readers might find out about it... 45 days later. Eventually 6925 became the new 7415 but it was not an easy time for pirate DXers during that transition.
We're a lot better off these days with tools on the listener side (SDR) and lines of communications in real time between listeners, and listeners and ops, at no cost. I'd also mention that we are a fairly tight community, and fortunately a lot of trust issues (to say things diplomatically?) that festered over the last decade or so have more or less dissipated as certain individuals have dropped out of the scene; pirate operators can feel reasonably comfortable dropping by the forums, or the chat, and mentioning that they are on the air. Hey, don't even tell us what frequency, maybe finding you would be part of the fun... so in other words, the chicken/egg problem Chris describes can be fairly safely overcome with some careful communication by the operator.
The nice thing about 4085 is that a lot of people are going to have antennas already for 75m and will be well suited to receive your signal, and perhaps even join in on the fun.
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i had a great experience using 5150Khz but the length of the horizontal dipole caused dependability and reliability issues as it kept breaking during wind and/or ice.
i think 5150-5200Khz (taking care to stay out of the 60m amateur band and keeping a sufficient "guard band" from 5130Khz) is a good compromise between the lower end of 4Mhz and the upper end of 6Mhz, you get the best of both propagation worlds, day and night plus, getting "noticed" is easier since WBCQ is at 5130Khz.
perhaps someday soon, I'll see if i can better support a horizontal dipole for 5150Khz but for now, 6880Khz will have to do until then.
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It's not like 7415 and 5130 are in use all the time.
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It's not like 7415 and 5130 are in use all the time.
not to throw this topic "too off topic" but you reminded me of a time during the weekday when i decided to broadcast for a few hours at 5130Khz when WBCQ was not broadcasting, matching the exact AM bandwidth used from WBCQ (slightly higher than 10Khz) and relaying their audio stream for 5130Khz, not a single person realized it was not WBCQ but an "imposter" ;D
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You cheeky barsteward!