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Messages - BoomboxDX

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151
^^^^^ True, the 49 and 41 meter bands are packed with Chinese and other Asian stations in the mornings when conditions aren't dead. I've only heard Europe over the pole or when conditions were better (i.e. 6-7 years ago or more).  Greece sometimes comes in on 9420 khz during the evening, however. How they do it when the rest of Europe is missing (even on the ham bands) is beyond me.

152
MW Loggings / Re: KVMI 1270 AM 0800 UTC 12 Jan 2020
« on: January 13, 2020, 0428 UTC »
Their signal arrives north probably 1/3 to 1/2 the nights I tune in 1270, and I'm in the PNW as you are. I also hear the Catholic station in Twin Falls ID a lot. And sometimes KBAM, Longview WA.

153
Propagation / Re: Poor conditions (noob)
« on: January 13, 2020, 0427 UTC »
Not an expert here, but the sun's output varies from day to day, even minute to minute. That's why the K and A indices change.

Why the effects of that difference in solar output varies from region to region, even in the same latitude, I wouldn't know.

The auroral radio zone can vary also, which is why northern latitudes have different prop than the more southerly latitudes.

154
MW Loggings / Re: KOGO 600 AM 0300 UTC 09 Jan 2020
« on: January 10, 2020, 0702 UTC »
Yeah, KOGO are pretty rare up here in the PNW on 600 khz. Good catch.

155
Equipment / Re: Harmonics
« on: January 10, 2020, 0658 UTC »
Nice that they got to it. Shows they care. There was an AM station on the other side of my state that had an audible ground loop on their signal for over a year.

156
Equipment / Re: Realistic (Radioshack) DX-394
« on: December 29, 2019, 1357 UTC »
That reminds me: there is apparently a trick to get the DX-394 to tune all the way down to VLF range. I can't remember how it's done, and although it apparently works, the radio's circuits aren't tuned for low ranges.... One would need a great antenna or other outboard piece of equipment to hear anything decently -- at least that's what I remember reading somewhere.

Another reason, perhaps, to consider the radio.

157
Amateur Radio / Re: Project 775
« on: December 26, 2019, 1406 UTC »
I read somewhere -- probably one of the ham forums -- that the 701 has some issues that have to be fixed when bought used. Some part that's hard to obtain, or one has to come up with a workaround. I don't recall what it was...

158
Equipment / Re: Realistic (Radioshack) DX-394
« on: December 24, 2019, 1533 UTC »
Good all around listening and SWL radio. Very sensitive. Won't need a massive antenna. I got worldwide reception on an indoor wire, about 20-30 ft (10 meters or so). The USB and LSB will be a khz or so off in the readout, which is no big deal -- it doesn't affect the performance of the radio. In high signals areas a longer wire probably would overload a 394, but there's an attenuator setting on the back of it.

High Z and low Z antenna jacks on the back of the radio, also came with a small whip.

Fine tuning is easy to use for SSB and CW.

Audio filters only (no variable RF/IF bandwidth). You don't notice it all that much for most applications. If you're into utes / data / etc., I don't know how it does for that. I used mine for SWL and ham monitoring, and it's an easy to operate radio.

The memories are easy to use. Mode switch is mechanical.

Some crosstalk if you have a ham station signal a few khz away that's extra strong, but in my case it wasn't that much of an issue.

If the DX-394 starts tuning in only one direction, squirt tuner cleaner or Deoxit down the side of the main tuner shaft. Enough will get into the rotary (mechanical) mechanism to clean it and stop the problem (in the past some on the internet claimed the main tuner mechanism is optical -- they are incorrect -- the parts list shows it's a mechanical tuner with physical contacts). This issue isn't common -- but when it happened to my 394 and I did some research there were at least two mentions online, and no one thought to squirt cleaner down the side of the shaft (it has just enough play to allow some through).

Ironically, I haven't tried my 394 on MW -- had other radios I've used for that. I know some guys have used them for MW. After an hour or so (? -- not sure of the time frame) some 394's will decrease in sensitivity on MW and you just turn the radio off and back on again, resets something in the microprocessor or another part of the radio and you're good to go again. The Yahoo 394 eGroup had a small article or post explaining the cause. Switching the power on and off is an easy fix, not that big a deal.

Some guys on the eGroup said 394s are easy to mod and/or work on, because of the layout. I did no mods on mine -- not into modding radios much, and surface mount doesn't agree with me.

Hope this helps.

Mine still fires up and works. It's a shame that the ionosphere mostly isn't. :-)

159
Propagation / Re: Updated Prediction for Cycle 25
« on: December 24, 2019, 0110 UTC »
Another 3-4 years until things pick up enough to really hear the world without a beverage. :-) Right now it sounds like nuclear winter propagation out there... although the other night there was some activity, a few nights before even WWV on 10000 kHz was nonexistent.

160
Amateur Radio / Re: Project 775
« on: December 24, 2019, 0105 UTC »
Thanks, kinda a icom rx nut from way back (arigato Inoue-san!) and they all seem to share a lot of the same design philosophy so you get to know part numbers, expected gain, etc. Started out with an R70 in '89 and a few months later with a 751. Had 735, 745, 751 and 751A, 765, 761, 756Pro and ProII, and lastly the 775 for tx, R70 and several R71s plus the R7000 for rx.

Not a ham here, obviously, but I see the famous IC-701 is missing from that list of Icoms. What's your opinion on that? I remember seeing the ads for it when it was a new thing, and it looked so cool. Almost made me want to become a ham to get one.

Interesting thread also.

161
Amateur Radio / Re: 30 meters
« on: December 24, 2019, 0057 UTC »

30m is packed every morning thru noon. FT8 is the preferred mode. At night, there are phone QSO's on ch 4 and 5 routinely. Lots of CW. You must be in a RF doldrum to not catch 30m daily.


From my QTH, yesterday morning I had PSKReporter pings from Indonesia to Siberia simultaneously, running 40w to a 120' wire 6' off the ground.

Phone? I was unaware that 30 meters was open to voice comms by hams. Did the rules change?

As for your comment about "RF doldrum", remember that in northern latitudes prop is usually poorer than in southern latitudes, due to the proximity of the auroral radio zone.

162
Amateur Radio / Re: 30 meters
« on: December 12, 2019, 0317 UTC »
I remember about 15-20 years ago it had a lot more activity. Now I just hear the odd RTTY sounding mode or some digital activity from time to time.

Generally, although there are apparently "more hams than ever" (at least, according to the two ham forum sites I frequent), most of them must just look at their radios on the way to the TV set. Or so it seems. Propagation definitely isn't helping things much, though.

163
General Radio Discussion / Re: YHWH
« on: December 12, 2019, 0314 UTC »
I haven't heard YHWH recently -- last logging was probably in 2015 or 2016...

But I thought that station got busted?

164
General Radio Discussion / Re: HD FM Audio Drives Me Nuts
« on: December 11, 2019, 0507 UTC »
The HD and analog paths are processed very differently.  Any lossy codec as a rule does not like clipped audio, as it contains more harmonic energy that it must process, with varying success.  Instead, look-ahead limiting is used, but as a consequence, produces some intermodulation distortion.  The analog path is processed conventionally.  The codec for HD also makes use of spectral band replication, which can cause all sorts of wierd artifacts on its own.  It all depends on what data rate the station has set their importer/exporter up for, and this is largely determined by how many HD sub channels they have.

There is a long standing theory that American DAB (HD) has a self-noising property.  Some more detail can be found here http://ham-radio.com/k6sti/hdrsn.htm

Also within the last few years, the Arbitron PPM system has been toyed with by several manufacturers in an attempt to boost the host stations' ratings.  They do this by making the PPM signal louder, and in many cases unmasking the tones.  It seems to be most noticeable on dry voice, and makes the announcer sound as if they are in a broom closet, or talking through a paper towel tube.  The device responsible for this is made by Telos, called the voltair.  https://www.telosalliance.com/25-Seven/Voltair

It's a race to the bottom.  The voltairs running on large corporate stations here have made the stations unlistenable for me.  My favorite station here switched on HD about 18 months ago, and I immediately noticed their audio quality drop.  Everything got sort of fuzzy sounding.

+-RH

But do stations use Voltairs on their HD channels?

165
The fallacy about the 5G story is that it is probably not practical the way it is described.  The high data rates described require even higher amounts of eNB (the cell site xcvr) baseband connectivity.  The short range of the RF transmissions means you need many more eNB sites than 4G...again requiring more baseband connectivity.  The physical supporting infrastructure costs to fully provide 5G coverage are staggering.  Most industry people think that 5G will only be fielded to urban areas where the density of the population can make the investment worthwhile.  Suburban and rural locations will likely only get 4G coverage.  5G will be primarily for the cities.  Even the CEOs of wireless providers have implied this.

Verizon has been bragging about how they have wired a dozen or so football stadiums for 5G.  The trade publications say that they haven’t been able to provide full coverage, even at the football stadium level.

Keep in mind that the 5G spec includes multiple frequency bands and many data rates.   Not all 5G systems are equal.  Some 5G implementations are much less breathtaking than others.  T-Mobile is looking at using 600 MHz for their system - their data rates will be  lower than those  in the high GHz range - but their equipment won’t be on the bleeding edge.

Interesting info here. This leads to a question: how much power is needed to operate a 5G system -- with all of its extra cell sites -- compared to the present system? Is anyone in the industry taking this into consideration? Right now the electric grids are almost maxed in some areas.

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