Why do California stations have such crappy sounding PW audio?

Discussion in 'Chat' started by W5HRO, Dec 17, 2015.

  1. W5HRO

    W5HRO Administrator

    Maybe its just me, but why do most of the AM stations, say like on 75-meters have such crappy sounding PW audio here in California?

    I've been in monitor mode for a long while now while I am still working on my gear and most of the stations here in the BA have really PW audio with very restricted frequency response. To be honest, most are very under modulated and they sound pretty much like shit! What is the deal? They guys on SSB here actually sound better ::)

    I guess I need to hurry up and finish everything and get back on the air. This is suppose to be the land of the big AM BC transmitters, but so far all I hear are PW stations with terrible restricted audio quality.
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  2. W1VTP

    W1VTP Member

    Just guessing but maybe a bunch of rice box AM wanna be's? The low level mod might be an effort to avoid ALC fold back. Just guessing. Spread the gospel of home-brewing or resurrected "real AM" boat-anchors of yesteryear out there in the land of the California Kilowatts.
     
  3. WD5JKO

    WD5JKO Member

    I got on 7290 last night around 7 pm CST before the band got too long. Worked a guy in Tennessee who was running a TS-590 into an Al-82 amplifier. He was an S7 to 9, low audio, and way too many lows. My noise floor was about an S6. He told me I was S9+20 and clear as a bell. I was hitting 150% positive peaks at 200 watts carrier output. I quickly fatigued trying to process his audio in my brain to extract words. So I went to 75M, and worked the 3870 Boat Anchor net on vintage SSB using my CE 20A with an E-34L pentode RF output tube. I could hear the W6's on 3869.4 running AM...they deliberately want to produce a beat note to the W5's running SSB. The band was going long, and the 5 area signals dropping. If I switched to my 15m vertical loop, I seemed to get a drop in noise such that copy was easier. Funny how my 40 watts PEP was again clear as a bell when I was struggling to hear the big guns. In both cases I was using my D104 with the highly modified K7DYY processor in the UG-8 base.

    Jim
    Wd5JKO
     
  4. W6MQI

    W6MQI Member

    I too personally hate AM stations with their full body audio with tons of lows doesn't work for me at all especially when conditions are marginal they just don't cut through the QRN. I'd say most, but not all are located in So.cal although they're few up here in No.cal as well not quite as prevalent though it seems.

    What's does PW stand for? There's a few meanings that come to mind just want to make sure I have the clean version.
     
  5. WD5JKO

    WD5JKO Member

    PW = Piss Weak!
     
  6. W1VTP

    W1VTP Member

    MQI & JKO: What bandwidth is your receiver running at? 6 KC is a bare minimum. Having asked that question, another point to be made is that the receive end should have a means of equalization - with adequate rx bw and rx equalization that's the first half of the successful HIFI AM operation. The other half is proper EQ at the transmit end includes a means of monitoring one's transmitted signal AF. One problem with proper tx EQ and a way to monitor off the air with a quality set of headphones and a means to reverse phase on the headphones because bone conduction in the head will artificially suppress the low end. In the wrong phase, the transmitter's EQ might be adjusted with too much bass.

    So there are things that need to be done at either end for successful HIFI audio (if, indeed, that's what we are talking about). One more point with. say, a 6 KC rx bw tuning should be done to place the incoming carrier at one side or the other of the rx 6 KC filter. So, if one limits one's tx af to from 300 to 3000 kc this "tubby" sound can be eliminated but if one wants to have both low end and high end for HIFI audio, response that proper operation must be performed at both ends

    Al
     
  7. W5HRO

    W5HRO Administrator

    Most of the guys I've been listening to here for the past 2 to 3 years are using old vintage gear, but their audio level usually sounds like they are running maybe 70% to 80% max so they always blend in or are just barely above the noise. They either have mostly lows with no highs or they have only midrange response with no lows or highs, and a few every now and then just have all highs and nothing else. Those are probably the rice-boxes.

    I have yet to hear anyone out here with full-range response that is LOUD with high-level positive going modulation.
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  8. W1VTP

    W1VTP Member

    Gotta AT LEAST have an O'Scope to monitor one's AM signal. There is an absolute requirement to toggle the polarity of the ingoing audio so the correct relationship between the positive peaks and the negative peaks are maintained.
     
  9. W6MQI

    W6MQI Member

    Could be part of the problem selectivity is stuck at 3.5, and 8kc. Could also be me my hearing sucks big time I've lost a lot of high, and low frequency response always having people repeat what their saying. I love operating CW used to be able to pullout those weak euro stations coming over the pole not anymore unless their strong its like listening to CW under water.

    Ah yes thanks
     
  10. W1VTP

    W1VTP Member

    OK Kirk.

    Yes, our hearing especially the top end can suffer as we get older. I have a serious notch in the 8 KC spot but then it comes back to up to around 12 KC. That makes a case for rx EQ - at least 10 band. That way you can compensate for any hearing loss. Other folks actually develop hearing problems where they hear two frequencies when only one is there. That may come from wax probs.. in the outer ear, or water issues inside the inner ear.

    I have a close friend who gave up high quality sound because his hearing got so bad he just could not handle the "distortion" that he heard even though that distortion is not actually there. But we are not talking about that here. Quality AM on the receive end involves good detection, good EQing and good drive either to high quality headphones or a high quality speaker and adequate rx bandwidth.
     
  11. W5HRO

    W5HRO Administrator

    Al,

    That's part of the problem. Too many EQ's inline resulting in over processed restricted audio quality. A lot of these guys I'm talking about are using BC mixing consoles and etc., but they sound like crap and are always very under modulated.

    If they would take all of that garbage out of line between their mics and their audio inputs and just design or modify their audio chains and modulators properly with the right coupling capacitor, bypass capacitors, and maybe (maybe) adding a little treble and bass control and then limit their negative peaks to around 90% then all they would need is a good high Z mic and that's it.

    What's funny is one of the locals here, GLH said a similar thing as I just did one night, but the problem is he has PW audio too wherever I hear him. You would think with all of the big equipment these guy have they would know how to put a decent and LOUD modulated single on the air to where it stands out and can really be heard. Unfortunately, I have yet to hear it. The guys on SSB here sound better and I'm serious.
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  12. W1VTP

    W1VTP Member

    OK Brian. I am not hearing that out here. Careful gain distribution can avoid may pitfalls. Just because a station has mixing / EQ consoles at their station doesn't = quality, full AM. If you ever come out here or if you could hook up to one of those remote listening stations, I can recommend several folks as examples of full great sound AM. I think of Steve, WA1QIX; Nick, KG2IR; Bill, W1LLY; Bob, K1KBW are good examples of good audio with good punch out here. An example of someone who uses NO processing and has excellent audio is Bob, W2ICQ. Bob has built his own speech amplifier and has a select D-104. So, it can be done either way but just throwing hardware in the station and hooking it up - yeah - probably that might not do the trick.

    It does take some skill, some careful management of our equipment and we can have full audio with excellent sound. It's been an excellent discussion for me. You make another point: SSBers CAN sound good. It does take some careful management of one's equipment. I have had some really great QSO's with Eric, WB2CAU on HIFI SSB. Frankly, with the exception of the action of the AVC that works on the SSB signal rather than the carrier I don't think you can tell the difference between a good sounding effective AM signal and the same thing in the SSB mode
    Al
     
  13. W5HRO

    W5HRO Administrator

    You are too far away from California to hear these guys on 75 or 160-meters anyway. Maybe on 75-meters during rare occasions when conditions are just right and the band is super long, but the way these guys run their audio it would be really difficult to hear them even then.
    ..
     
  14. WD5JKO

    WD5JKO Member

    My Gonset G-76 receiver is fairly narrow in bandwidth; perhaps 5 Khz @ -6DB. An AM signal with some highs surely brightens up when I offset the tuning a little. Many folks just are too close to the noise, and wider BW or offset tuning does not bring up the highs. My thinking is many are using the stock Rice Box mobile microphone with little or no equalization. A dynamic microphone IMHO when unequalized is not suitable for communication purposes unless the significant Tayloring of the audio is achieved between about 80 to 3800 hz. A stock D-104 MC-320 element does just that when loaded into something around 2 meg-ohms. Sure there are those that say 5 meg, or 10 meg, but then we move that high pass -3 db down point below 50hz....not good for communication.

    Then the Rice Boxes don't care about the speech polarity. With a 50-50 chance, my luck says I'm phased backward every time. If your voice is kind of ragged (asymmetrical), then the phase being backwards makes a huge difference. The OM has to crank the audio down to keep out of the ALC. Now the average modulation (upward) might be under 50%.

    When I use my Flex 3000 on the same signals, the carrier blip might be 3 divisions above the noise (30 db), yet the modulation seen is almost always 500 hz and down. The audio above 500 hz is below the noise floor. Using receiver EQ is a nice option to have, but in the instance described, it doesn't help. The problem is at the transmitter end. It doesn't matter if the OM has a $10,000 transceiver. Then I hear someone like Donald Chester K4KYV, and he is always armchair copy. Yes he is strong, but more importantly Don pays attention to many things ignored by the appliance operator.

    Listen to the AM stations out west. Here is a Sedona, Arizona web based SDR receiver:
    http://w7rna.dyndns-remote.com:18901/

    AM on 7293 right now.

    Jim
    Wd5JKO
     
  15. W1VTP

    W1VTP Member

    Jim

    Pretty much agree with you on your comments. I think you hit the nail on the head with the use of "appliance operators." Had a nice visit from Don KYV this summer and he's quite the gentleman. I've know Don since he was up here in Cambridge, Ma back in the '70's. Unfortunately, his and my schedules don't match and our on the air contacts have been sporadic. We AMers out here are very patient with the new comers when they first come on with their rice boxes. I have seen some folks start out with very crappy audio with ALC control dipping the carrier on voice peaks and by the time they get through they sound pretty good.

    You have hit on the crux with your mention of your viewed spectrum on these guys having most of their power 500~ and below - a fact that is missed by many. Careful adjustment of one's equalization usually results in a lot more power going out to the higher frequencies but, still, there is room for the lower frequencies.

    The D-104 is a much misunderstood microphone. The problem may be that many of these mics are OLD and have been subjected to shock from dropping, being stored in a hostile environment and such. I have two D-104's and one of them is trash while the other one is OK. The beauty of the D-104 is that it has a built-in "presence" frequency response. It's a great mic when properly loaded and the polarity is proper - BTW that polarity coming from a D-104 is not the same head to head and has to be checked in a case to case basis.

    I see you are in Texas. I have a friend John N2OLA who lives in Spring, Tx - not too far from you, I think. I'll try to see if I have a recording of Bob, W2ICQ somewhere. He's an excellent example of how good a D-104 can sound

    Later, Al
     
  16. W6MQI

    W6MQI Member

    That's a handy receiver to listen in on we use it from time to time. There's a couple other SDR's up in the north west that are good too.
     
  17. W5HRO

    W5HRO Administrator

    I've said this time and time again, but nothing sounds better in regards to high-level plate modulation than an octal tube speech amp driver setup that uses low mu triodes as the drivers to drive the final modulator tubes. All you need with that is a D104 and nothing else. Then limit the negative peaks on your RF final(s) to 90% thus increasing the positives ones.

    All you have to do is tweak the coupling and bypass caps in the amp to fit your voice as long as the D104 is looking into a 1M to 10M maximum load. You can get great low-end and high-end response both. As long and you see 125% average positive modulation you won't have any problem being heard.

    Example tube lineup: 6SJ7 to a 6SK7 to a 6N7 or 6SN7’s to 2A3’s/6A3’s/6B4G’s to the final modulator tubes.

    Out of all the old junk transmitters that were made back in the 1950’s for example the old Globe King 500 had the best sounding modulation of them all. It was a problematic piece of junk, but it sounded superb on the air. All of the other junk transmitters like the Johnsons, Heathkits, etc. never had the audio quality the GK 500 did. It didn’t have the compression/AVC tube after the 6SJ7, but it still sounded better than most everything else that was made back then. None of the Collins stuff was worth a shit for audio quality either. Mostly all space-shuttle military grade type audio.

    Any transmitter that has that kind of a tube-line up and setup will still sound better than just about anything else you can put on the air on the ham bands to this day, including any equipment using modern technology. The only other thing that might sound better is a properly designed linear amp setup that uses no audio iron.

    This falls into the same category like when trying to compare other guitar amplifiers to a Fender Champ amp. The Champ amp still rules to this day.
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  18. W1VTP

    W1VTP Member

    Here are some examples of stations out here in the NE. Steve, WA1QIX usually has a very strong signal but there are other stations with limited BW and weaker signals. Tim, WA1HLR is the benchmark for making anything sound good. I think he was running an ART13. Steve is running a modern class E station (as am I).

    Be sure to use some decent speakers. Received on a Flex 1500 with the BW set at 9 KC in the sync AM detection mode.

    Merry Christmas, Al
     

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  19. W5HRO

    W5HRO Administrator

    But you are giving examples of the guys I'm not referring to. You are giving examples of the two guys who actually know how to do it.

    I've heard Tim sound a lot better than that so the ART13 setup doesn't do him justice. Steve's class E audio is super clean and sounds like he's using a condenser mic. It's probably not, but it sounds like one. He runs over 100% on the positive side and has enough on the high-end so you wouldn't have any problem hearing him over long distances.

    Anyway, I'm off to the casino today and to do some Xmax shopping so I will be back tomorrow, unless I reply from my iPhone, which I might.
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  20. W1VTP

    W1VTP Member

    OK. I forgot one guy until he checked in after the net. This is Rich, K1ETP. This is his Yaesu FT-101 (E?). He is running it into an Ameritron ALS series solid state amplifier. So, rice boxes can sound decent. Same receiver, same BW settings

    Al

    PS: Timmy's rig was a Globe Scout going into an amplifier. I stand corrected on that point. Timmy has been "lurking" on this thread. Here are his remarks to the West coast. Here's an example where a HIFI station goes into the noise. Normally, I would tighten up the filters for clarity. This would have worked with Timmy as he has plenty of energy in the 2 to 3 KC region
     

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  21. W5HRO

    W5HRO Administrator

    You could have left that recording off AL because it sounds so bad. His signal was too far down in your noise level.

    Anyway, Globe Scouts won’t sound near as good as the Globe King 500. It has a 6SJ7 going to a 6J5, but that goes into a crappy 6L6 so forget it. It's not a low mu triode driver setup with the iron. The only Globe Scout (Deluxe?) transmitter I have ever heard that sounded really good was Bob's, W0CAB's with the modified Heising modulation. He made that one sound awesome. I forget what he did to it, but he somehow got full response Heising out of it and you could tell it was real Heising.
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  22. W1VTP

    W1VTP Member

    Yeah, Timmy was pretty much in the mud. Dunno why he does that. He keeps talking about the Blockbuster but it's a no-show. You oughta hear hear what the "dreaded TCS" sounds like - then there's the SBE transmitter (SideBand Eliminator) which is a MOPS the wibble and wobbles through the passband as he scrubs off the slopbuckets like barnacles from the QSO

    Well, that was fun. I didn't get a chance to record Bob, W2ICQ as he was a no-show on the AWA PM AM net this Sunday

    Al
     
  23. W5HRO

    W5HRO Administrator

    You know what, I now remember the GK 500's didn't come with a 6B4G driver in them. They came with a single ended 6L6 and the older ones a 6F6.

    When you mentioned the Globe Scout with it’s 6L6 my memory has all of a sudden come back. I was thinking of a mod people did like Ken, N5AVU because of the crappy 6L6. He had modified his with a single 6B4G into the 811's and maybe used a UTC transformer for coupling instead of the stock one, but I cannot remember for certain. I do know he had a 6B4G though and not a 6L6 and the 811's were still at "0" grid bias, I think....
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  24. W1VTP

    W1VTP Member

    My most recent post which I asked be deleted: I ran into one of those clueless type who was using a Heath SB-1400. He couldn't copy my HIFI Collins 32V1. "Too bassy" was his complaint. I extricated myself from the QSO and found something else to do. These guys do not have the wit to tune to one side of their 2.4 KC BW filter to gain the best freq response and then wonder why they have a problem with quality AM.

    There. I got it off my chest. I'll try to get a recording of my Collins for posterity sometime. I guess my take is that if one is to gain the best from the AM experience he needs to put some effort into it. It is not an appliance operator friendly mode.

    Al
     
  25. W5HRO

    W5HRO Administrator

    That reminds me of the 2 or 3 hams that always told me I sounded distorted. They were always using their R-390A's in the 4kc position ::)
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