The AM Forum

Has anyone heard from Tolly recently?  I haven't seen him post for a while. Hope everything is OK on his end.

I've been wondering the same thing
for the past few days, Bob.

According to his avatar,
Tolly lives in northern California
which really got hammered with
a lot of rain and wind in the past
couple of weeks. I hope he and
his family are okay out there.

Think he's on vacation.

http://amfone.net/phpBB2/viewtopic.php?t=3962

Right you are!  He even posted his
itinerary and I see he's in San Diego
until the 4th.  And here we were
worried about him.  Pshaw!

I recall him talking about it now that you mention it.

I wouldn't mind being in San Diego, myself...
Think I'd be here instead of seafood bars on the wharfs?

Ahhhhhhhh

I am still here, actually... ;)

But I am working on design of audio equipment, no radio projects currently. Have some prototypes and would like to start manufacturing, but the problem is I am an engineer, and don't know how to do business... Need help...

I was in a start-up company for 3 years creating high-volume consumer products.

One thing I learned is that there are A LOT of wealthy people/investors out there looking for the entrepreneurs and start-ups.   Put together a good business plan for presentation to the bankers and other entrepreneurs and the rest is synergy.  As I recall you are in California, a lot of electronics business expertise there.

The only thing is, right now with the recovery from the Great Recession, the banking system is disfavoring the small businessman.

Make sure you visit Murphy Surplus. lots of small parts and hardware.

Thank you guys!

That's why I did not use any loans for my small business, but it will be needed for a big one, to engineer, manufacture, distribute and support.

Hi there, I am back! :D

Since my last visit, I was pretty busy.

If you don't remember, here is my story.

Back in 1970'Th I used to be a student of an Institute of Automated Control Systems and Radio Electronic, TIASUR. Audio was my passion, I played in a rock group, and designed for it amps, guitar effects, synthesizer, mixers, etc... I thought when I graduated in 1981 that I know precisely what is needed to get the best audio reproduction, that tubes were obsolete, transistors were the best. My last audio amplifier then delivered 200W per channel, I thought that it was perfect, and nothing better can be done...

...until in 2002 in a small high-end store in Walnut Creek, California I dropped my jaw when heard as if a real Diana Krall playing and singing. The amp was single ended with 211 output triodes, something like 10W per channel, and very inefficient Magnepan speakers, huge like doors. It was not loud, but soo reeeal, I got goosebumps, and sphincters almost unleashed!

Since then I started again, with vacuum tubes, trying to get as real as possible sound reproduction. I had my day job in software development industry, but could not shake off the desire to make my own high end equipment. My previous experience with tone shaping for rock group appeared handy, instead of creating audible musical distortions I felt and knew what is needed to make distortions as if to disappear. And now since my job is my passion, I am eager to bring to the market what I finally earned to do: affordable equipment of high end quality of sound reproduction.
In short, Back in 1980 I designed what I though was the best amplifier. It was 200W per channel fully complementary ultrafast wideband opamp.
In 2004, after hearing in 2002 real high end for the first time in my life, I designed 100W per channel push-pull amp with military output tubes.
In 2009 I designed 100W per channel hybrid amp with augmented SiC source followers loaded on modulated CCS,
and finally in 2018 come to 6W per channel single ended amplifier, with regulated power and 3 nested feedback loops.
Well; I forgot to mention that I did not jump from 100W per channel transformerless hybrid amp directly to 6W per channel amp. Between them were 5W per channel triode class A2 amp without feedbacks, and 45W per channel single ended class A2 pentode amp with 3 nested feedback loops, similar to current 6W per channel amp, but much more expensive, and consuming half a kilowatt of electricity constantly. While I love my 45W per channel amp with military transmitting output tubes, it consumes more than half of kilowatt electricity, and I found it impractical, since high end quality speakers with 92 dB/W/M and better sensitivity are widely available, and 6W per channel amp is quite adequate, and many of NOS and current production tubes are available for such amps.

https://www.youtube.com/results?search_query=wavebourn

Wow Tolly,

What a surprise, you really jogged my brain cells!

I remember the high-powered emitter follower outputs.

Good luck in your new endeavors.  I just retired.

Wow! A blast from the past. Welcome back!

Interesting to find you here!

Except that 6W with a 92dB/1/1m speaker is not particularly adequate... unless ur listening at night at very
low levels. That provides for a max SPL at 1 Meter, not at the listening position of under, less than 98dB.

Even with 109dB/1W/1m compression drivers 6 watts is not going to pass un-clipped or uncompressed
peaks.

How do I know? Maybe I've been there, done that... :D

Btw, I had no idea that ur a ham...

Thank you guys!

In January I moved to Texas and registered my new company. However, Coronavirus changed all plans, so instead of working on preamps and power amps that I planned to manufacture, I am preparing some UV-C disinfection lamps...

Thank you my dear for your opinion. It is as always strong and no-compromise. :-)

To me, and to many audiophiles that I  met, normal listening level is 95 dB peak, and a couple of 6W channels with 92 dB/W/M speakers in a listening room can produce that easily.
However, I wrote that at least 92 dB/W/M sensitivity is enough, and plenty of such speakers are available. If you believe that the only way to have high end audio is driving 80 dB/W/M bookshelf speakers with 1 KW amps, I respect your opinion, since there can be only 2 opinions, yours and a wrong one. :D

Yeah... It was what, like 2001, when I made that hybrid, with 8AL9 tube and a MOSFET source follower? :-)

After that I made it augmented, to keep S-D voltage almost signal - independent, and then loaded on counter-modulated CCS to keep the current through it stable. The amp sounded gorgeous, but consumed more than kilowatt for 2x100W output. :-)

Now I have a different problem.
UV-C is good for disinfection. But due to it's disinfecting nature, it is bad for skin and eyes. So, the obvious solution to fool-proof it is to add some sensor of presence of people and pets. I tried a PIR sensor to pause it, but it is not as reliable as I want.

There are Doppler-effect based miniature microwave radars, some work in 3 GHz, some in 10 Hz bands.They remind me my diploma project back in 1981, when I designed a microwave alarm system. It used a machined head for 10.7 GHz, with Gunn and mixing diodes.
This Chinese devices are much simpler, and use BCB traces as resonators.

The question is, which frequencies are permitted by FCC, and do I need to get a special license, if the transmitted power is like 20-30 mW?

I think of trying the simpler, cheaper solutions first. How about infrared sensors - a system like the in-home motion detectors?

Yes, and it is what I tried the first, PIR. It did not satisfy me. It turns movement into AC via multiple lenses on the surface of the semi-sphere. Not as sensitive as I want, and not reliable. It is good to power on security lights, when you do not care about how soon it reacts. But here the reaction must be immediate.

And microwave sensors are cheaper than PIR ones. (https://www.ebay.com/itm/10Pcs-RCWL-0516-Microwave-Radar-Sensor-Human-Body-PIR-Motion-Detector-Module/173974044046)

Hi Tolly,

   I bought a Chinese made UV-C lamp that comes with a stand, and a remote control gizmo that has buttons to select the run time, 15, 30, and 60 minutes.

I tried it out in the master bedroom with the adjoining bathroom. I left the HVAC off, and had the lamp on for 60 minutes as the XYL and I were going to do some shopping.

When I came back, the ozone level in the room was really strong. Had to ventilate the room, but even at that, the bathroom and closets stunk for about 10 days.

I've heard that certain UV-C lamp wavelengths either enhance, or minimize ozone generation.

As I see it, my lamp is dangerous!

Jim
Wd5JKO

Hi Jim;
usual UVC lamps generate 185 and 254 nanometer strips. 185 nm has energy of photons to ionize oxygen and generate ozone. It does not go far, being absorbed by oxygen, while 254 nm go far and destroy organics. When bulbs are made from clear quartz, they pass both. Some additions work as HPF, so only 254 nm goes through such glass.
The samples of lamps that I have generate both wavelengths, and I have plenty of such spare bulbs. But ozone-less bulbs can be ordered also as replacements.

Ozone is good to kill mold in gaps where rays do not come. However, it smells like storm, and in high concentration is harmful. When I come back after shopping, I open the door of my trailer for venting.

They do make PIR/Ultrasonic combo units.  Those are near instantaneous.

And you're very right about the crappy effects of UV on skin.  I've worked on some industrial sized units for water purification.  Yuck!

Look into dual mode motion detectors.  I've installed hundreds of them in commercial and residential locations.   California now requires them damn near.  We even have to have some plugs in a room switched on and off by motion or vacancy detectors to meet title 24!

--Shane
KD6VXI

Thank you Shane, can you give me some more information, what kind of units, where to find them?

Well... you have done some very interesting things with audio, and certainly have good and interesting ideas.

I suppose my opinions on these matters are strong, because they are well-formed both in theory and practice over a long
time.

It seems to me that it is misleading to say that 6 watts are sufficient and that 95dB is a typical listening level.
PERHAPS it is a typical average listening level. Sure. But unless ur willing to accept compression due to hitting
the triode's non-linear region (assuming that feedback doesn't force linearity up to the point it hits "the wall"), 6 watts is
both theoretically insufficient and practically so. You know it too.

Peaks on well recorded music can be ~20dB over average. Do the math on how much power is required?

You know that too.

As I said, with a 109dB/1w/1m compression driver on a quality horn, 6 watts is barely passable.
How many times have I had the fun of running low power SE amps on horns? Lots.
Other speakers too...

Well, I can pull out this card, now that I am becoming an old buzzard!
I started with hifi, in the business back in the early 1970s, and was listening to
stuff I could only drool over and never afford back in the 60s.

The people I know were doing triodes in the 1980s, trying every possible combination we could
come up with... long before almost anyone was thinking that tube amps were any good. (Except
the Japanese!)

It's fine if you like the resulting sound. But the average person is probably going to go down
the "low power" rabbit hole and not be very happy.

Suggest working this amp into ~100dB/1w/1m LF drivers and matching that to some sort of similar
or greater sensitivity HF section.

It's kinda like the guys who try to get on AM with an Isopole antenna and 25watts out of a transceiver??
Not really a good combination.
Somewhere in there you still need to put the RF into the ionosphere - you can do it with a high efficiency
antenna (read: BIG ASS wide spaced beam up 150ft or more) and low power, OR you can maybe do it
with a low efficiency antenna and GOBS of power. In the end, it works out to the equivalent of needed
certain SPL in the room... sort of...

So, what about ham radio?
AM ham radio?

                                     _-_-

Please read again, I wrote only what I wrote, i.e. 92 db at least, and 95 dB peak is a normal listening level for myself and many other audiophiles that I know. I never said that it is enough, and neither questioned your personal preferences. :-)

Well, people were doing triodes in 1980Th... ;-)

I understand why, and I respect what they were doing.

There are people who do restoration of vintage cars, and if there is the demand, they make copies. It is their business, not mine.

300B triodes were designed when people knew not much about sound reproduction, capacitors and resistors were quite expensive; it was cheaper to wind transformers and chokes.

In order to get linear sound reproduction they designed special tubes, compromising amplification factor for linearity and low output impedance. They were especially crafted tubes to use in as simple as possible amplifiers. The end result of such amplifiers depends very much on particular tubes. In order to get stereo amplifier you have to match many tubes to find one matched pair. To get better sound you have to select better tubes. Why Western Electric 300B tubes are so expensive, because they were made to sound best in simple amplifiers where everything relied on tubes. Such amplifiers can nor drive properly any speakers. They need speakers that have particular mechanical damping.

However, today we know more, resistors and capacitors are cheaper than in 1930'Th, and can design amps that do not require so strict selection of 300B tubes, but what's the point then if their major properties are not used? For modern amps more convenient tubes are available, they are much cheaper, and are in current production.

For example, in my Edelweiss-3 I can use 6L6, 5881, EL34, KT77, KT88, KT120 tubes, adjusting self-bias by a single potentiometer observing bias on digital gauges under tubes. I can select high output impedance for "current drive" of some speakers like pentode amplifiers without feedback do. For other speakers I can select medium output impedance like triode amps (including 300B) have. I can select low output impedance to drive modern hi-fi speakers that want solid state amplifiers. Or even negative output impedance for servo-damping of speakers making frequency response on bass frequencies more even and extended.

Frequency response of my amps is pretty wide, from 6 Hz to 90 KHz, without special output transformers that cost today a fortune.

And gain of both channels stays the same, no matter which tubes you swap. Dynamic distortions are minimal thanks to solid state voltage regulation and other measures I took while designing my amps. No such "bloating" on overload like in typical 300B amps. No audible hum.

I.e. I design my amps in 21'St century, you can compare them to 5-10 times more expensive amps with 300B tubes and see for yourself, which would you prefer for listening, reliability, and easiness of usage, when you don't need to roll awfully expensive tubes to get clean sound that you love.

And once again, my amps are not SET. They use 2 pentode stages with 3 nested feedback loops, to get transfer curves especially crafted, similar to what Western Electric were getting specially crafting tubes.

In short, Western Electric were trading gain of the tube for desired transfer curves using precise internal geometry. I trade gain of pentodes using external components for similar transfer curves, to get better results cheaper. :-)

Here you can find some demos of my Edelweiss-3 amp prototypes (https://www.youtube.com/user/Wavebourn/videos)

I did read it, and said that 6 watts, no matter what the preference is insufficient, I said why. Done with this topic, ok?


Incorrect. Caps and resistors were not expensive compared to transformers and chokes at that time.
The 300B was designed by Western Electric's Bell Labs.
You can read the literature, it is free and online now. Bell Labs Journal.

They had available larger tubes as well.


Historically inaccurate.
The 300B was not designed as a tube for audio amplifiers.

Western Electric designed amplifiers used feedback and did not rely upon close matching
of tubes.

Western Electric tubes are expensive TODAY because not that many original examples survived
into the latter part of the 20th century, far fewer were ever made compared to things like the
807 or 6L6. They were more expensive in the 1960s than a similar power RCA or GE tube (for example).
And they produced less power in a typical circuit, at a time when making power was an important
criterion. So, not nearly as popular.


As you ought to know there are some very nice Ruskie sweep tubes that when their grids and screens are
tied produce lovely, superior to 300B even, curves.

IF curves are your criterion??


This is a very nice feature.
Why is it named Edelweiss?
If he is a designer/engineer, I don't think I am familiar with him.
More information is appreciated.
You can PM, or email, since this is clearly not ham radio related at all!


This is a very strong claim.
I'd like to see your square wave at 1kHz for example - using a fast square wave as input...
for example from the calibrator on a 100mHz Tek scope or equivalent.
I scratch my head at the idea that common output iron will reach 90kHz on a good day going
downhill... (again feel free to email - I won't bite!)

<snip>


Nested feedback loops will lock the thing in... up to a point. And it is a perfectly valid approach to
design.

I'd suggest you look at the harmonic spectrum out a ways to see what you've actually got going.
Love to see a screen shot both at low power (under 1 watt) mid power and within a fraction of
a dB of "the wall"... but again this is not a ham radio topic.

Anatoliy, I don't have a personal love of the 300B. Imho it has a particular flaw. One that can not
be eliminated by any known means. I think there are better tubes in a practical sense.

You may be shocked to know that my amplification typically is solid state of my own design.
And most of that, now relatively anciently produced.
I am retired. :D

Worn out from these endless "debates" on audio. Don't care any longer. Something close to 98% of
all "audiophiles" I think have significant hearing deficits, so they'll never hear what I used to be
able to easily perceive. So, I can't hear what I used to either - now I know what they all
are hearing now... HA! It's a bad joke. To me anyhow.

Doing ham radio.
Much more fun now.

So what are you doing in HAM RADIO??


attached is an image of my DC coupled 35w/ch SE MOSFET amp from about 1995... for reference.
(thus the heatsinks)

Well; in 1995 I was still on my computer - related career path, developing TCP/IP and Unix based network for Kamaz corporation, and offering Internet access for the whole town. Fighting against phone companies for channels, while they were trying to convince the management of the corporation that X25 is the way to go, while TCP/IP does not follow standards of OSI/ISO. And it was 1995 AFAIR when first sources of NCSA Mosaic and CERN HTTPD become avilable, and I implemented first Web-based information system for top management of the corporation.
Speaking of audio, It was still my hobby, but I still believed that vacuum tubes are obsolete, and ICs are the only way to go. :-)

Why I am here, on the forum? Because back in 2001 I liked to listen radio, but found that all bands become dirtier and dirties, but being a former physicist and electronics engineer with a diploma, I could not give it up, and gradually come to tube inputs with strong passive preselectors, then bought vintage 1930'Th Meissner radio receiver and restored it. I sold it to the member of this forum, and bought BC-348, then R390A/URR. I even wanted to get my ham license, but did not have a time for that. And then I was bit by a high end bug and started my vacuum tube path. Well, it was not just "starting" actually; being a kid I used to repair tube radios, then TVs. Back then they were common, transistor radios were new and something special. :-) And of course, I was taught by my professors to design using vacuum tubes, but I thought that I will never use them. :-)
I built my first guitar amp back in 1974 when I was a teenager, it was a tube amp, with Gu-50 output tubes. In order to drive them I added a twin 6N6P triode between concertina phase splitter and output tubes. I did not know that "re-invented" Williamson design then.
And there was no better choice back then to find a forum with well informed and enthusiastic people than this one. And the fact that it is still alive is the best proof.

I know that you followed me on DIY Audio forum questioning almost all my sentences, and AFAIR, you were among people who drove me out of the forum that now is called Prodigy, for my heretical questioning of famous vintage designs that they were cloning. But I hope that you would allow me to stay here, even though I do not have a ham radio license. :-)

You are most certainly welcome, from me to be here!

As far as "driving you out"? No, I don't think that ever happened.
I do not know what forum is now called "Prodigy"??
The only audio forum I was ever active in, other than (back many decades ago) USENET, was DiyAudio.com.
I ceased to participate there some years ago, as my life simply led in other directions...

I rather think I did not question you on questioning others use of traditional designs.
However, I would question absolutist statements, unless they were on solid ground.

What we may have is something of a native language user vs. learned language user ?
I don't know for sure.
But for example you used to tend make, and did in this thread now did make categorical, and un-tempered,
unmodified absolute statements. And expect them, I guess (?), to just pass unchallenged.

It is one thing to say, for example, "...I find that I am more than satisfied with what i hear
when I use a 6w amplifier on my true 92dB/1w/1m speakers..."  So, I might ignore such
a statement, as it is not one of fact, it is one of belief or preference. Aka, not
"textbook", unambiguously true. (and/or backed up with empirical tests or similar...)

And, of course I would ask, similarly as I have, how that would work when the headroom is
lacking? BUT, when one makes a categorical statement that non-experts who are
reading will likely take as gospel, then IF I happen to have substantive knowledge
to the contrary, it makes sense to post it for their sake!

I would do the same if the topic were ham radio - but we don't find much if any of that, not
that I am aware of here.

Does this make sense at all?

Btw, please do get a ham radio license!

With your training and technical background it ought to very very easy.
The test can be more or less memorized, if necessary.

RF and AM phone is just about as much fun as banging one's head against the
audio wall!  :o

Enjoy!

                    _-_-bear

Think of all the fun ur missing!!

You end up doing stuff like this:

Well;

let me repeat, 92 dB sensitivity in a living room is enough for me and many audiophiles that I know, but it is the minimum for 6W/Ch amp. Of course, higher sensitivity is better. And it never clips, do not compare it to other amps! It gracefully saturates, fooling imagination, so instead of distorted it sounds as if "too loud". Playing with regimes of tubes and 3 nested feedback loops I got a transfer curve that resembles non-linearities of our ears. However, the best result I got with 6CB5A tubes, 6550 are not so realistic.

A friend asked how Edelweiss-3 would play with his 90 dB/W/M JBL speakers. I said that it would not be enough for realistic loudness. He brought them and tried nevertheless. The amp could not deliver the loudness to match a real performance. After that we connected his speakers to my Gubernator-71 45W/Channel SE amp, with Edelweiss-3 preamp, and were blown up by an orchestra sounding in my living room, as if in a philharmonic hall. :-)
There are no miracles: want to drive lower efficiency speakers getting high end sound quality, be prepared to spend money on an amp (once) and electricity (always)!

Here is the video on Facebook (https://www.facebook.com/Wavebourn/videos/367824073893300)

Anitoliy,

The topic here is AM ham radio...

I'll leave you to talk about the audio issues over on DiyAudio or some other suitable
venue. Facebook? Ok?

If you wish to email me, you can click on the email near my avatar.

So, let's talk ham radio!
What do you think about joining the ranks on-the-air?
And have you ever fired up WebSDRs?

                          _-_-bear

Well; it is QSO, and the topic is, where's I been. Thank you anyway for your invitation. :D

Still, the question reminds unanswered. What charges can I face if sell UV-C lamps that protect users from rays using 3.5 GHz 30 mW radar?

People need them, and need ASAP. Who can I contact to get an exception?

https://www.google.com/search?q=pir+ultrasonic+motion+detector

Will return many different styles.  Both wall, ceiling and standard Decora style.

From there, pick and choose what would work.

I typically use ceiling mount, low voltage (with 'power pack and low voltage dimming) for work, which is probably useless for you.

A normal Decora style if it could be incorporated in your design maybe?

--Shane
KD6VXI

Wow! Thank you Shane, I did not know that they are in production!