RadioReference on Facebook   RadioReference on Twitter   RadioReference Blog
 

Go Back   The RadioReference.com Forums > HF / MW / LW Monitoring > HF/MW/LW General Discussion


HF/MW/LW General Discussion - General discussion on monitoring the HF (High Frequency), MW (Medium Wave), and LW (Long Wave) spectrum (0.5 - 30 MHz)

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 04-11-2018, 7:24 AM
AlphaFive's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Apr 2011
Location: Asheville North Carolina
Posts: 549
Default HF digital use

Just was reading another post that was asking about FM use on HF. It brought up another question to my mind, somewhat unrelated. If FM use is very limited other than 10 meters, then, is AM used in digital mode? Certainly FM above 30 Mhz is largely in that format, what about AM below 30? I truly do not mean to sound like a simpleton, but I really don't know, and I'm not ashamed to say I don't know. Is AM digital in use?
__________________
"I am serious, and don't call me Shirley" - Dr. Rumack 1980
Pace 1000B Pro 2020 Pro 34 Pro 94 Pro 197 BCD536HP TRX 2
Reply With Quote
Sponsored links
  #2 (permalink)  
Old 04-11-2018, 7:34 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2002
Location: Wichita Falls, TX
Posts: 7,026
Default

Are you talking about amateur or commercial/government/military?
Are you talking about sending modem generated audio tones on double sideband AM?

In the ham world it's mostly direct FSK (RTTY) or sending audio tones on SSB.
Some of the modes like PSK don't have a constant amplitude but are not considered AM.

I have never heard of anybody using full carrier AM for digital on HF.
That would take up twice the bandwidth as the same signal on SSB.

The only time I have seen FM used for digital was back in the 80's some of us were running 1200 baud packet on 10m FM.
__________________
Tom
Reply With Quote
  #3 (permalink)  
Old 04-11-2018, 7:41 AM
AlphaFive's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Apr 2011
Location: Asheville North Carolina
Posts: 549
Default

[QUOTE=nd5y;2914910]Are you talking about amateur or commercial/government/military?
Are you talking about sending modem generated audio tones on double sideband AM?

I have never heard of anybody using full carrier AM for digital on HF.
That would take up twice the bandwidth as the same signal on SSB.

That one answered my question.. I should certainly have been more specific. I was really referring to voice modulation, either amateur use or some of the independent high power broadcasters that I read about. Like always, I appreciate your help, you provide an answer even I can understand, haaaa. Take care.
__________________
"I am serious, and don't call me Shirley" - Dr. Rumack 1980
Pace 1000B Pro 2020 Pro 34 Pro 94 Pro 197 BCD536HP TRX 2
Reply With Quote
  #4 (permalink)  
Old 04-11-2018, 9:25 AM
Member
  Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2002
Location: Wichita Falls, TX
Posts: 7,026
Default

Quote:
Originally Posted by AlphaFive View Post
I was really referring to voice modulation, either amateur use or some of the independent high power broadcasters that I read about.
Some Icom radios can operate D-STAR on HF but I don't know how popular it is.
AOR still sells these ARD9800 | OTHER PRODUCTS | AOR U.S.A., INC. Authority On Radio Communications but I don't think many people have them.

I'm not familiar with commercial HF.
Some broadcasters use DRM but I don't know much about it either.
Digital Radio Mondiale | The future of global radio
https://en.wikipedia.org/wiki/Digital_Radio_Mondiale
__________________
Tom
Reply With Quote
  #5 (permalink)  
Old 04-11-2018, 9:46 AM
AlphaFive's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Apr 2011
Location: Asheville North Carolina
Posts: 549
Default Digital HF

Thank you for the links, I'll look it over..
__________________
"I am serious, and don't call me Shirley" - Dr. Rumack 1980
Pace 1000B Pro 2020 Pro 34 Pro 94 Pro 197 BCD536HP TRX 2
Reply With Quote
Sponsored links
  #6 (permalink)  
Old 04-11-2018, 10:03 AM
Wiki Admin Emeritus
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2002
Location: Bowie, Md.
Posts: 20,875
Default

It's not really AM - the modulation is much more complex than that. And while DRM is used on HF, there are very few broadcasts actually aimed our way. But before we get to that...

DRM - The RadioReference Wiki

There are several ways to modify HF receivers (some, at least) to work with DRM, and a few SDRs also have this capability. The modifications are, in principle, very similar to what you would do to tap a scanner to get baseband audio for various decoding purposes.

Mike
__________________
links editor, Utility Monitoring Central
HF Forum moderator, RadioReference
Friends don't let friends buy Scancat Lite Plus!
Reply With Quote
  #7 (permalink)  
Old 04-11-2018, 2:24 PM
AlphaFive's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Apr 2011
Location: Asheville North Carolina
Posts: 549
Default digital HF

Thank you for that. I have seen many references to DRM, have to admit I never took the time to read anything about it. Now I have, and will learn a little more also. Thanks muches, take care.
__________________
"I am serious, and don't call me Shirley" - Dr. Rumack 1980
Pace 1000B Pro 2020 Pro 34 Pro 94 Pro 197 BCD536HP TRX 2
Reply With Quote
  #8 (permalink)  
Old 04-13-2018, 3:02 PM
edweirdFL's Avatar
Member
  Premium Subscriber
Premium Subscriber
Amateur Radio Operator
Amateur Radio
 
Join Date: Dec 2004
Location: Daytona Beach, FL
Posts: 286
Default

I seldom operate or hear D Star on HF outside of the scheduled nets on Saturday and Sundays.
__________________
TX/RX = TH-D74A IC-W32A IC-T7H IC-7300 IC-7100 FT-817ND
RX = BCD996T Pro-96 Pro-97 OS535(2) IC-R7100 Pro-90 AR8000
Reply With Quote
  #9 (permalink)  
Old 04-13-2018, 3:30 PM
Wiki Admin Emeritus
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2002
Location: Bowie, Md.
Posts: 20,875
Default

No ham stuff here, edweird. There's another forum for that.

This is HF broadcasting we're talking about here...thanks Mike
__________________
links editor, Utility Monitoring Central
HF Forum moderator, RadioReference
Friends don't let friends buy Scancat Lite Plus!
Reply With Quote
  #10 (permalink)  
Old 04-13-2018, 3:48 PM
majoco's Avatar
Member
  Shack Photos
Shack photos
 
Join Date: Dec 2008
Location: New Zealand
Posts: 2,633
Default

DRM is almost a dead duck now. It was touted as "FM quality over shortwave radio" and indeed it was - the few times I managed to receive the only useable signal to me was from All India Radio. RNZ had a DRM transmission to the Pacific but I was too close of course. The cost of equipment to the broadcaster was too high as well so you'll be lucky to hear any HF broadcasts now. It also required a special receiver which put it out of reach of target audiences

DRM on ham bands - I very much doubt it - too much bandwidth required and specialised equipment.
__________________
Cheers - Martin ZL2MC - Palmerston North
Reply With Quote
  #11 (permalink)  
Old 04-14-2018, 6:51 AM
Wiki Admin Emeritus
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2002
Location: Bowie, Md.
Posts: 20,875
Default

It's used on the ham bands, just not very much due, in part, to specialized gear. This it OT here, of course, but check out WinDRM

Mike
__________________
links editor, Utility Monitoring Central
HF Forum moderator, RadioReference
Friends don't let friends buy Scancat Lite Plus!
Reply With Quote
  #12 (permalink)  
Old Yesterday, 12:33 AM
Member
   
Join Date: Apr 2018
Posts: 6
Default

Quote:
Originally Posted by nd5y View Post

I have never heard of anybody using full carrier AM for digital on HF.
That would take up twice the bandwidth as the same signal on SSB.
actually there's a cuban numbers station (HM01) that uses a digital mode (RDFT) on an AM carrier. i thought it was the weirdest thing when i saw it in my SDR waterfall. there may be other stations/countries that do something like this, but the cuban one is the only one i've seen on the air.
Reply With Quote
  #13 (permalink)  
Old Yesterday, 7:05 AM
AlphaFive's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Apr 2011
Location: Asheville North Carolina
Posts: 549
Default HF digital

That one is very interesting, and great information to put in a file. I ask the initial question about AM digital, because it will assist in my decision about obtaining my first actual receiver. The essential question being, "If below 30 Mhz is nearly exclusively AM, is there a need to obtain a modern receiver that would include AM digital modes"? I am learning now that there really is not widespread use of any particular system that is both digital and AM, as exists in the world of FM. All of the posts are very much appreciated, and very helpful to me. Thank you all, the day is getting much closer for me to have enough saved up to jump in the deep end... Can't wait.
I would add that at this point and time, my only interest exists in simple voice modulation, am not ready for, or have any interest yet in the world of decoding systems..
__________________
"I am serious, and don't call me Shirley" - Dr. Rumack 1980
Pace 1000B Pro 2020 Pro 34 Pro 94 Pro 197 BCD536HP TRX 2

Last edited by AlphaFive; Yesterday at 7:22 AM.. Reason: ref. voice modulation
Reply With Quote
  #14 (permalink)  
Old Yesterday, 7:41 AM
Wiki Admin Emeritus
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2002
Location: Bowie, Md.
Posts: 20,875
Default

This question really belongs in our HF equipment forum - and the discussion on this topic should be there...however...

There are only a few SDRs and rare portables that can cover DRM natively, so that shouldn't be a consideration. That's the only voice digital mode HF broadcasters use (there are a few others used by hams). And while AM is widespread, sideband use is equally widespread in the utilities and ham worlds. If you don't get something that is sideband capable - and you can do that easily with portables like the Tecsun PL660 - you will be short changing yourself when and if you find your interests change - and they often do in this hobby.

To be continued in our HF equipment forum...Mike
__________________
links editor, Utility Monitoring Central
HF Forum moderator, RadioReference
Friends don't let friends buy Scancat Lite Plus!
Reply With Quote
  #15 (permalink)  
Old Yesterday, 7:46 AM
AlphaFive's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Apr 2011
Location: Asheville North Carolina
Posts: 549
Default AM

Thank you, glad your here to guide me in the right direction (forum)... haaa, take care
Reference the sideband availability. In researching receivers over a long period, it seems as though I rarely ran across a unit that wouldn't include sideband coverage. Anything I have marked in red on my "list of consideration" would certainly include the sideband coverage. I do find that interesting and would really like to delve into that also. Thanks for your help
__________________
"I am serious, and don't call me Shirley" - Dr. Rumack 1980
Pace 1000B Pro 2020 Pro 34 Pro 94 Pro 197 BCD536HP TRX 2

Last edited by AlphaFive; Yesterday at 7:56 AM.. Reason: sideband discussion
Reply With Quote
  #16 (permalink)  
Old Yesterday, 8:17 AM
AlphaFive's Avatar
Member
  Premium Subscriber
Premium Subscriber
 
Join Date: Apr 2011
Location: Asheville North Carolina
Posts: 549
Default HF digital

I'll go ahead and toss this into the mix. I've already decided what's best for me, and my particular situation. I will be limited to my high and clear wooden attic, too many outdoor antennas already in the mix. I'm going with the Alinco DX R8T/E, and hooked up onto an SA7000 antenna. That will set me up for future expansion into a wider range receiver. Really enjoy the loop offerings. The SA7000 will allow me not to have to concern myself with null effects. I was, and still am trying to learn about AM and FM availability. I find the world of HF, SW MW and LW to be fascinating. Don't know much, but always wanting to learn. As always, thank you all for your help
__________________
"I am serious, and don't call me Shirley" - Dr. Rumack 1980
Pace 1000B Pro 2020 Pro 34 Pro 94 Pro 197 BCD536HP TRX 2
Reply With Quote
  #17 (permalink)  
Old Yesterday, 6:35 PM
Wiki Admin Emeritus
  Amateur Radio Operator
Amateur Radio
 
Join Date: Jul 2002
Location: Bowie, Md.
Posts: 20,875
Default

All right, to get this back on topic, I'm fairly sure there's a R8T Yahoo group out there somewhere- so if you get interested in DRM, those folks are likely to have the mod procedure

Good Luck..Mike
__________________
links editor, Utility Monitoring Central
HF Forum moderator, RadioReference
Friends don't let friends buy Scancat Lite Plus!
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 3:52 PM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
All information here is Copyright 2012 by RadioReference.com LLC and Lindsay C. Blanton III.Ad Management by RedTyger
Copyright 2015 by RadioReference.com LLC Privacy Policy  |  Terms and Conditions