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Author Topic: Dumb it down for this crusty, 72 year old fart still, for the most part, living  (Read 2618 times)

UncleJohn

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...in analog land).
     Recently I went to wikipedia & also did a google search asking "what is/are SDR transmissions?" I almost fell out of the chair here @ the local library in a catatonic trance attempting to understand what I was reading. But 1st. B 4 U answer let me relate something:
     I recall in the past the Voice of Vietnam would beam a signal up to a satellite & then beam same signal down to a xmit. site in Sackville, Canada, then Sackville would xmit. original signal to N.A. Is this method similar to SDR? Or not? Is the "internet" Involved?     Also, is it WWCR that rebroadcasts programs from foreign countries for listening in the U.S.A. ? Is this something similar to SDR?
     Please try to dumb any response (s) down. The library staff already has plenty to deal & put up with even crustier old farts who refuse to wear a face mask PLUS "transients", "Homeless", & "Title Ten" types whom the library generously & compassionately allows to use computer internet access! "Umkay!?"

Elf36

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Not sure if I'm answering everything. SDR is an acronym for 'Software Defined Radio' SDR's use software for the modulation and demodulation of radio signals and typically have better, more finer ways of cleaning up signal etc. An SDR can be a receiver or a transceiver. Most of the time when you hear people on hear talking about an SDR, they are talking about units such as RSP , Airspy, HackRF etc. These units hook up to your PC and are capable of using indoor or outdoor antennas. They have a ton of features and amazing capabilities that most table top receivers do not have. You can also listen to online SDR receivers almost anywhere in the world via the internet. As far as the last part- There are still many shortwave relay stations all over the world, including the U.S. Some newer folks get confused when they are listening to programs from China, Romania, Iran etc and think that the signal is traveling directly from that specific country. Although there are plenty of stations that can be received from thousands of miles away when propagation is good. When I listen to Radio Romania or the BBC at my home in Florida,it is direct. I listen directly from other locations outside of the U.S as well. For me online or relay stations aren't  very exciting, but they serve a good purpose for other folks. Hope that is what you were looking for.

Offline Stretchyman

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SDR us just a different method of Rx and Tx. Used to be done with analogue methods (see Superheterodyne) now All modern receivers and transmitters use SDR in full or in part of the chain.

SDR is also far simpler to implement as only requires 2 chips.

Check out the Twente SDR in the Netherlands (there are 1000's of others btw) but on the main page shows the receiver, 2 chips, simple eh! and receives the whole of the HF spectrum at once.

What you were describing is a REPEATER albeit the signal would have been digitised to go up to the satellite link. Analogue hasn't been used for a very long time!

I'd buy a cheap SDR and have a play. You can actually 'SEE' the signals you want to listen to, great fun and far better than twiddling a dial endlessly!

Str.
'It's better to give than receive' so why Rx when you can Tx!

                                              ;)

UncleJohn

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Gentlemen, thanks for the info. I do not have a computer & thus no internet & my QTH. I'm a nostalgic person... I Still have my radio logs back beginning in 1964 when I got a Zenith Royal 500 8 Transistor for Xmas. I would listen endlessly for new stations, caught KDKA, WHO, WLS, & all the more near by stuff & Canada from @ upbringing home near PDX. No "F"ing digital noise to put up with, either! I prefer my R8B bought directly from R. L. Drake, Com. back in 2001. Picked up many more Pirates back then since I had a Very Long wire antenna outside.  Those were the days.   ::)

Offline BoomboxDX

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If you've got an R8, you probably have all the radio you need. Most of the broadcast DX activity is on MW, and the Drake R8 is the standard for MW. SDRs have a fancy display and a few features the R8 might not have, but an R8 is hard to beat.

SW has been mostly half-dead since the solar cycle dipped about 5-6 years ago. Some nights and mornings there is still much to hear, and if you're in the PNW (WA, OR, etc.), you'll hear Asia many (if not most) mornings on 41, 49, and 31 meters -- reception of those stations, of course, will vary because of the low solar cycle. But aside from the occasional nights where SW is actually working well, MW is the place to be for DX.

"SDR", technically, is "software defined radio". In other words, a chip in the radio has software inside it that acts as a radio processor -- these chips that contain this sort of software are also often called "DSP chips". They replace the analog IF chips in radios which were standard from the mid 1970s to the late 2000s. My Sangean AM-FM radio (a PR-D5) that is playing South Asian music from 100-200 km away right now as I type this, has a DSP chip inside. The processing of the signal I am hearing wasn't done via the superhet, analog method that IF chips used. The DSP chip instead is doing all that via digital processing software.

Your average DSP radio chip has an RF amp inside, along with an analog to digital converter; software that tunes, filters, decodes, etc,; which then goes into a digital-to-analog converter, which is sent to an audio chip.

An "SDR" in usual parlance is a computer program that runs on a laptop or desktop computer that uses the same sort of chip but has an interface that puts it all up on a fancy looking screen with virtual buttons and a 'waterfall' display.

Hope this helps in some way.
An AM radio Boombox DXer.
+ GE SRIII, PR-D5 & TRF on MW.
The usual Realistic culprits on SW (and a Panasonic).

Offline fpeconsultant

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I have no experience with SDRs (they call me a "knob turner" - oh well), but I must agree about the R8.  I bought mine around 1998 and it WAY outperforms my Ten-Tec RX340, Watkins Johnson HF-1000, and the JRCNRD545.  And that's on SW, MW, LW, WeFax, etc.  My R8 is always my go-to radio.  I had to send it to a guy a few years ago to get something fixed (a capacitor I think) and he re-calibrated it and it is like new.  Too bad they don't make them anymore.  Its all SDRs nowadays - but then again, I griped when cassettes took out 8-Tracks.
Have fun,
FPE
Near Chicago, IL USA.  Drake R8, Ten-Tec RX340, JRC NRD545, Watkins Johnson HF-1000, Wellbrook loop at 28', 43m inverted vee.  Please QSL to fpeconsultant@aol.com thanks.

UncleJohn

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Gentlemen...Thanks to BoomboxDX & fpeconsultant for the input. It's encouraging to know that my R8B is so highly regarded in the DX world. I partly based my purchase decision on articles in Monitoring Times reviewing the Drake. Both part a & b are available for download (I only had part a). Yup, a nice "Communications Receiver" as opposed to labeling it simply a "radio". I once considered  a "525" but eventually didn't. I once owned a Panasonic RFB600, the display eventually quit displaying for some reason...I just shit-canned it. Oh well. I agree, mw/am is best nowadays. But mostly I hear "talk", "sports", "sports", & "talk", maybe a little music & religion & more sports&talk! Fortunately I Love to read! Again, Thanks! 73's!
« Last Edit: September 30, 2021, 2313 UTC by UncleJohn »

Offline M R I

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I like my Drake R8B so much I modified it with a switchable extra wideband filter mode beyond 6 Kc for Hi Fi audio. I also bypassed the 5 Khz low pass audio filter on one of the line out RCA Jacks ( going to a Hi Fi system)  the other Jack is stock. This includes fatting up the low end sound caps too. I added a higher stability ajustable TCXO too. It has one of the best sync detectors like the Sony ICF-2010.
Mix.Radio.International [at] ProtonMail [dot] com

Offline Stretchyman

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If your serious about listening to Dx or any radio related thing I really think getting a cheap 2nd hand pc and an SDR is a no brainer. Filtering is infinitely superior to any analogue method + the noise reduction is helpful in saving your ears! You can see a large portion of any band instantly and record and playback the same for later analysis. Analogue reception unless your in the boondocks and especially if your near a city is near impossible with the noise generated by modern electronic devices. I've personally gone halfway and use an SDR on the I.F. o/p of my receiver..

J.
'It's better to give than receive' so why Rx when you can Tx!

                                              ;)

Offline RobRich

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The R8B is an excellent desktop receiver. Congrats on the good choice. :)

https://www.google.com/books/edition/Passport_to_World_Band_Radio/RFmNuzg3ufAC?hl=en&gbpv=1&dq=Drake+R8B+Passport+to+World+Band+Radio&pg=PA161&printsec=frontcover

https://www.eham.net/reviews/view-product?id=494



Given my selection of receivers, I am probably going to be using my Airspy HF+ Discovery if truly needing fine-grained selectivity for some reason.

The stock wide filter in my Kenwood R-2000 is wide enough and the skirts shallow enough that it is pretty good for music content. It has been my primary MW/HF receiver for many years, so its sound profile what I am used to hearing anyway. I have standalone DSPs from MFJ and Timewave available to cook the audio if needed.

Though I rarely use it, actually my vintage National NC-125 with matching speaker is perhaps one of my "best sounding" receivers for MW/HF music assuming decent signal quality.

http://wd4eui.com/National_125.html
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' Loop-on-Ground | 31' Vertical | 18' End-Fed Vertical | 9' NCPL | PA0NHC MiniWhip

UncleJohn

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Just if anybody's interested you can download Part 1 & Part 2 Monitoring Times, May & June 1998 articles comparing the two Drakes (haha get it Two Jakes/ though Chinatown was better, IMO) though I just tried via google-no luck This Time. Maybe one of you more savvy internet-experienced fellow dx'ers can. "Chow".

UncleJohn

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The R8B is an excellent desktop receiver. Congrats on the good choice. :)




Though I rarely use it, actually my vintage National NC-125 with matching speaker is perhaps one of my "best sounding" receivers for MW/HF music assuming decent signal quality.

http://wd4eui.com/National_125.html

Like I said, I'm a bit of a nostalgic person so IF you ever decide to sell it? If the price IS right...?  8)
Wow, I'm actually gettin' pretty good @ this editing stuff... ;)
« Last Edit: September 30, 2021, 2322 UTC by UncleJohn »

Offline RobRich

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They might be available elsewhere, but Scribd has both copies of the Monitoring Times.

https://www.scribd.com/document/374637105/Monitoring-Times-1998-05
https://www.scribd.com/document/374637100/Monitoring-Times-1998-06

Scribd is a paid service, but a 30-day trial is available if anyone is interested. Looks like a 60-day trial coupon code might be available, too.

https://www.retailmenot.com/view/scribd.com



My NC-125 is in great cosmetic condition, and from what I can tell, likely even better than the one I linked. I took a gamble on a ~$200 eBay purchase a few years ago. IIRC, it was like an antique store offering it, so I figure few buyers wanted to take the chance. I was rather surprised with it being in working condition, though I do need to get around to doing some deferred maintenance.

Last time I used it the VFO knob was slipping after warming up, but thankfully the internal VFO and frequency display were both tracking okay if turned inside the cabinet, so it should be a minimal fix.... with the usual non-zero chance of turning into a multi-hour annoyance for me. Fun stuff.

The bigger job is doing a checkout on the capacitors. I suspect they are not originals since it actually works. ;) Still, I have no idea how old they are.

After the caps I might as well do a basic alignment. It is stable but somewhat off frequency. I have been doing the lazy method of just offsetting the bandspread.
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' Loop-on-Ground | 31' Vertical | 18' End-Fed Vertical | 9' NCPL | PA0NHC MiniWhip

Offline BoomboxDX

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UncleJohn, MW DX has been less than it was early last decade, like SW it began to dip around 2016.

MW still has a lot of DX, but it will pick up as the new solar cycle progresses, so don't lose hope on hearing some good catches. The guys who get the best catches now have beverage antennas or big loops with amplifiers.

In 2011-2014 I was hearing all sorts of stations on my MW DX radios that I don't hear now. Cuba's Radio Rebelde on 1180 (behind a regional station and KOFI Kalispell, used to be heard many nights, although I had to listen through the other signals to ID it. I even heard it on a Realistic TRF with no extra antenna.

Rebelde, unfortunately, hasn't been heard here in 5-6 years on MW. KVNS Brownsville on 1700 used to be a regular, although it would mix with XEPE (Baja California). I haven't heard KVNS in a while, either. Periodically, I get a new station, so not all is lost. But yeah, there is a lot of talk and ranchero music on the MW. I'm just glad the signals are there. SW sometimes is mostly empty.

As for choice of radios, I prefer my Superadios or my Panasonic RF-B45, sometimes with a tuned loop next to them, as the slightly wider selectivity (around 6 khz I think) helps ID stations. My PR-D5 has narrower selectivity but it sounds a little muddy, and sometimes you need to hear a bit more to ID a station, even if there is more splash. It's always a flip of the coin, I guess.
An AM radio Boombox DXer.
+ GE SRIII, PR-D5 & TRF on MW.
The usual Realistic culprits on SW (and a Panasonic).

Offline NJQA

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They might be available elsewhere, but Scribd has both copies of the Monitoring Times.

https://www.scribd.com/document/374637105/Monitoring-Times-1998-05
https://www.scribd.com/document/374637100/Monitoring-Times-1998-06

Scribd is a paid service, but a 30-day trial is available if anyone is interested. Looks like a 60-day trial coupon code might be available, too.

https://www.retailmenot.com/view/scribd.com




You can find free copies of Monitoring Times back issues here:

https://worldradiohistory.com/Monitoring-Times.htm