varicaps?

[Joerg]

On 2020-04-02 10:21, John Larkin wrote:

On Thu, 02 Apr 2020 09:32:36 +0300, upsidedown@downunder.com wrote:

On Wed, 1 Apr 2020 16:30:55 -0700 (PDT), Phil Allison
pallison49@gmail.com> wrote:

[...]

News to me.


... Phil

50 kilowatts of radiated RF must be expensive. 5G will probably take
over everything at a huge energy saving.

No, it's just that the energy then comes out of the bank account of the
recipient, to pay for the pricey cell package. And where I was today 5G
would not have reached anyhow (access only on foot, via mountain bike or
on a horse).

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Phil Allison]

John Larkin Bullshitted Wildly Again:

-----------------------------------

50 kilowatts of radiated RF must be expensive.

** Transmitters are rated in EIRP - not actual watts.

Antenna gain is added to the actual number used to get EIRP - it can be ten times higher with VHF and UHF.

5G will probably take
over everything at a huge energy saving.

** Laughably absurd crap.

JL has totally lost the plot.



..... Phil

 

[whit3rd]

On Thursday, April 2, 2020 at 3:13:55 PM UTC-7, John Larkin wrote:

Why do people make 15 volt varicaps and only give cv data up to 8
volts?

I'm not totally certain, but the tempco of a varicap is similar (and opposite) to
the tempco of a 30V Zener, which is why lots of TVs have a 30V supply to the tuner.

The other possibility is that the characteristic curve of the varicap runs out
before it gets near breakdown. The sweeping out of charge from the
depletion region is highly dependent on the doping, and getting
near-linearity in sensitivity over the range is why 'hyperabrupt' doping
was invented.

So, either the curve gets ugly at 8V, or the whole process line is optimized
for 30V (and low-V spec operation gets good yield using lower breakdown).

 

[George Herold]

On Thursday, April 2, 2020 at 2:46:37 PM UTC-4, piglet wrote:

On 02/04/2020 6:05 pm, George Herold wrote:
On Thursday, April 2, 2020 at 12:02:46 PM UTC-4, piglet wrote:

Ah yes of course, we had fun last year disecting the AD310 parametric
input op-amp which used back to back transdiode (CB-E) bjts as varactors.

piglet

Ahh, parametric amps... be fun to build one.
Is there some easy way to make a (demonstration) para-amp from
the really crappy ceramic caps?

George H.


Varicap diode paramps (like the AD310 we enjoyed last year) have pF
scale capacitance and were driven in 00s kHz or lo-MHz but since the
ceramic caps with large voltage coefficient are uF range I like to think
one could get away with power line frequencies. Which opens up the
delightful steampunk idea I sketched here...

https://www.dropbox.com/s/jqubvy92xuc2788/mains_paramp_idea.pdf?raw=1

'Oh dear, piglet you're making my brain spin.'
said pooh.
I have trouble with all these transformer circuits,
doing modulation / demod (at 1/2 freq?) / and low pass detection..
Is that six diode bridge thing doing double duty?
No forget that part... let me ask about the front end.

So let's assume we have balanced the (vari)caps so at zero
V-in each C is the same. Then each 60 Hz 1/2 cycle there is the
some current flowing... I guess we'll want the caps to be the major
impedance limiting the current... then with voltage and unbalanced C's
there are different currents in each 1/2 cycle. And that looks like
some 2*f (120 Hz) 'modulation' that proportional to V-in... is that
close to right?

I must admit I never know exactly how to think about a transformer.

George H.

Of course if the input varactor caps aren't closely matched the offset
voltage could be of the order of volts but still the DC input bias
current is near zero! And 60Hz pump frequency rather limits GBW and
output slew rate!

piglet

 

[whit3rd]

On Thursday, April 2, 2020 at 11:46:37 AM UTC-7, piglet wrote:

Varicap diode paramps (like the AD310 we enjoyed last year) have pF
scale capacitance and were driven in 00s kHz or lo-MHz but since the
ceramic caps with large voltage coefficient are uF range...

https://www.dropbox.com/s/jqubvy92xuc2788/mains_paramp_idea.pdf?raw=1

Of course if the input varactor caps aren't closely matched the offset
voltage could be of the order of volts

The ceramic caps that have large voltage coefficient ALSO have hysteresis;
the phase won't be right at the decode transformer. So, regular-old-diodes
make a bit more sense. And, at 100 kHz, the driven windings won't
need so very much fine wire (transformers get smaller and much less
expensive). That also makes shielding and decoupling easier.

Mostly, your target circuit is what's in a MiniCircuits ADE-6+, if you go to
a higher drive frequency...

<https://www.minicircuits.com/pdfs/ADE-6+.pdf>

 

[John Larkin]

On Thu, 2 Apr 2020 16:32:54 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

John Larkin Bullshitted Wildly Again:

-----------------------------------


50 kilowatts of radiated RF must be expensive.


** Transmitters are rated in EIRP - not actual watts.

Antenna gain is added to the actual number used to get EIRP - it can be ten times higher with VHF and UHF.



5G will probably take
over everything at a huge energy saving.



** Laughably absurd crap.

JL has totally lost the plot.

I remember 300 baud acoustic modems. Before there was an Internet.
Progress keeps happening. Things are kind of messy now but will get
better. Not many people get their TV off the air any more around here,
and AM/FM radios are mostly for cars... now.

Actually, I designed some 75 baud modems. Now I'm working with SFP
modules at 10 Gbps.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Rickie C]

On Thursday, April 2, 2020 at 7:21:13 PM UTC-4, Joerg wrote:

On 2020-04-01 17:29, Rick C wrote:
On Wednesday, April 1, 2020 at 7:31:01 PM UTC-4, Phil Allison wrote:
Joerg wrote:

-------------

Up to about 30pf they'll likely remain. Skyworks and such. Those
with large capacitances lost their market.



** AM radio has disappeared ??

News to me.

My car doesn't even receive AM, only FM, Sirius XM and Slacker
Internet radio.


I would not want that radio in my car. I listen to AM most of the time
when driving, and not just then.

Good thing it's not your car then. You would have to invest in a radio from the dollar store.

Not much on AM. Talk shows mostly. They don't interest me. If someone recorded and distilled them down to the very few interesting callers and guests, it might be worthwile, but nothing to pass a couple of hours listening to live.

I'm a big fan of Slacker these days.

.. Oh, and bluetooth from your phone. But no AM radio.
I think they could do that 100% in software if they wanted to. It's
only 1600 kHz max frequency.


Well, they don't go that far but everything is PLL or DDS nowadays.

Of course, because FM is a bit high frequency to do in software. XM even more so. AM only requires a crystal diode, a coil and a capacitor.

There simply isn't a need any longer for large capacitance varicaps to
run the local oscillator. As for the preselector (adjustable filter in
front of the mixer), that has fallen victim to the red pencil of the
bean counter, which has cost performance when in the vicinity of other
strong signals.
The bean counter is affected by strong signals? Wow, that must be some seriously strong signals.

I drive right by an FM station antenna and never seem to have any trouble. Oh, you are talking about those MW AM stations that are quickly becoming obsolete.

--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[Rickie C]

On Thursday, April 2, 2020 at 7:23:20 PM UTC-4, Joerg wrote:

On 2020-04-02 00:01, Rick C wrote:
On Thursday, April 2, 2020 at 2:23:36 AM UTC-4, Chris Jones wrote:
On 02/04/2020 10:30, Phil Allison wrote:
Joerg wrote:

-------------

Up to about 30pf they'll likely remain. Skyworks and such.
Those with large capacitances lost their market.



** AM radio has disappeared ??

News to me.


... Phil



If someone were designing an AM radio these days, quite likely
they would use a chip for the radio receiver circuitry, and those
quite likely would have a PLL with the VCO integrated on the chip,
e.g. TDA7786. So, the market for discrete varactors suited to the
AM band may have gone away regardless of whether AM radios stay
popular.

Maybe for the base level Honda Civic and the Yugo. These days you
get an XM radio if you want it or not and the same electronics
receives AM/FM without an extra chip. That is likely why AM was left
out of the Tesla radio. It's not worth the bother of adding the
passives required to filter the band.


Maybe because Tesla drivers aren't supposed to be listening to Rush
Limbaugh?

I didn't realize he is AM only, but that seems about right.

I remember when he was accused of telling Floridians to ignore the hurricane warnings and not to evacuate, then flew out of the area. So I went to his web site where they have transcripts of his shows. He didn't tell people to ignore the warnings. He mostly flapped his gums about the stores charging more for water and batteries after they sold out and it was very hard to get fresh supplies sent down the peninsula. THEN he flew north to safety..

The biggest take away I got from reading the transcript, which can be done with much more dispassion, was that he, much like Trump, seldom says anything. He talks around issues with tremendous inflection and emotion so as to inflame his listeners,,, but seldom says anything material.

It's the idiots who listen to him, letting themselves be riled up into a frenzy. I've had conversations with Trump supporters/Limbaugh listeners who love to spew sound bites, but can't actually discuss issues. They just flip to the next sound bite. I would focus on a single issue, not saying anything, just asking questions until it was clear the issue was bogus. But then she would flip to the next sound bite. After doing that three times I realized you can't argue logic to someone who is emotionally vested in a conclusion.

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

[Phil Allison]

John Larkin is Losing His Mind ....

-------------------------------

50 kilowatts of radiated RF must be expensive.


** Transmitters are rated in EIRP - not actual watts.

Antenna gain is added to the actual number used to get EIRP - it can be ten times higher with VHF and UHF.



5G will probably take
over everything at a huge energy saving.



** Laughably absurd crap.

JL has totally lost the plot.



I remember 300 baud acoustic modems. Before there was an Internet.
Progress keeps happening. Things are kind of messy now but will get
better. Not many people get their TV off the air any more around here,
and AM/FM radios are mostly for cars... now.

**See:

https://www.youtube.com/watch?v=E7WQ1tdxSqI



..... Phil

 

[Rickie C]

On Thursday, April 2, 2020 at 7:26:21 PM UTC-4, Joerg wrote:

On 2020-04-02 10:21, John Larkin wrote:
On Thu, 02 Apr 2020 09:32:36 +0300, upsidedown@downunder.com wrote:

On Wed, 1 Apr 2020 16:30:55 -0700 (PDT), Phil Allison
pallison49@gmail.com> wrote:

[...]

News to me.


... Phil

50 kilowatts of radiated RF must be expensive. 5G will probably take
over everything at a huge energy saving.


No, it's just that the energy then comes out of the bank account of the
recipient, to pay for the pricey cell package. And where I was today 5G
would not have reached anyhow (access only on foot, via mountain bike or
on a horse).

I don't know what the big deal is about 5G. It is faster cell phone service so that in dense cities you can pay the cell phone companies for all your data needs rather than paying the "cable" companies for the same thing. I suppose some people watch movies on their cell phone, but really? It's not really anything you can't get now, except it will be from the cell companies instead of the cable companies.

Larkin is funny. Talk about math challenged... 50 kW radiated is around $0.25 per hour. Factor of 2 from efficiency issues - hell make it 4 - gives $1 per hour. Maybe that's why he doesn't seem to understand electric cars.. He can't even do the math of how cheap they are to run. I wonder if he ever looks at the electric bill from his business.

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

 

[whit3rd]

On Thursday, April 2, 2020 at 6:29:51 PM UTC-7, Ricky C wrote:

> Larkin is funny. Talk about math challenged... 50 kW radiated is around $0.25 per hour.

Huh? 50 kW radiated is close to $5 per hour around here. Heck, you could get
A PARKING SPOT DOWNTOWN with that much money.

 

[Phil Allison]

Ricky Cretin is Absurd wrote:


---------------------------
On 2020-04-02 10:21, John Larkin wrote:

50 kilowatts of radiated RF must be expensive. 5G will probably take
over everything at a huge energy saving.


Larkin is funny. Talk about math challenged... 50 kW radiated is around $0.25 per hour. Factor of 2 from efficiency issues - hell make it 4 - gives $1 per hour.

** Really?

In the USA, domestic power cost about 12c per kWH

I expect a big user would get a discount, say to 10c per kWH

50 x 10 = 500 or $5.

Maybe that's why he doesn't seem to understand electric cars.

** Pot calls Kettle ??

" Tesla is not a brand, it's a Cult".



... Phil

 

[Michael Terrell]

On Thursday, April 2, 2020 at 7:32:59 PM UTC-4, Phil Allison wrote:

John Larkin Bullshitted Wildly Again:

-----------------------------------


50 kilowatts of radiated RF must be expensive.


** Transmitters are rated in EIRP - not actual watts.

Antenna gain is added to the actual number used to get EIRP - it can be ten times higher with VHF and UHF.



5G will probably take
over everything at a huge energy saving.



** Laughably absurd crap.

Yes, you are. There are losses in the antenna system on the AM Broadcast band. Gain in an antenna system comes from compressing the signal, and reducing the coverage area. While there are directional arrays for AM BCB, the FCC license is expressed in the measurable field strength, witch has to be tested in an annual 'Proof of Performance' test. The AM transmitters are sold, based on the actual wattage, not some mythical fairy units that you've dreamed up. Once you've been the Chief engineer, or 'Engineer of Record' for newly constructed stations, then you will know what the hell you are talking about. WLW didn't get 500KW in the '30s from antenna gain. It was an actual 500KW transmitter, fed into a classic Blaw-Knox diamond shaped tower.. That transmitter still exists, in its original location near Cincinnati. It was a engineering miracle, of its time. I toured this site almost 50 years ago to today. Here are some photos of how it was done. It puts your puny little guitar amps to shame. <http://j-hawkins.com/wlw.shtml>

 

[Michael Terrell]

On Thursday, April 2, 2020 at 9:29:51 PM UTC-4, Ricky C wrote:

On Thursday, April 2, 2020 at 7:26:21 PM UTC-4, Joerg wrote:
On 2020-04-02 10:21, John Larkin wrote:
On Thu, 02 Apr 2020 09:32:36 +0300, upsidedown@downunder.com wrote:

On Wed, 1 Apr 2020 16:30:55 -0700 (PDT), Phil Allison
pallison49@gmail.com> wrote:

[...]

News to me.


... Phil

50 kilowatts of radiated RF must be expensive. 5G will probably take
over everything at a huge energy saving.


No, it's just that the energy then comes out of the bank account of the
recipient, to pay for the pricey cell package. And where I was today 5G
would not have reached anyhow (access only on foot, via mountain bike or
on a horse).

I don't know what the big deal is about 5G. It is faster cell phone service so that in dense cities you can pay the cell phone companies for all your data needs rather than paying the "cable" companies for the same thing. I suppose some people watch movies on their cell phone, but really? It's not really anything you can't get now, except it will be from the cell companies instead of the cable companies.

Larkin is funny. Talk about math challenged... 50 kW radiated is around $0.25 per hour. Factor of 2 from efficiency issues - hell make it 4 - gives $1 per hour. Maybe that's why he doesn't seem to understand electric cars. He can't even do the math of how cheap they are to run. I wonder if he ever looks at the electric bill from his business.

The electric bill for WACX TV in the late '80s was over $45,000 a month for their NTSC 130 KW Comark UHF transmitter. It was running at least 162 hours a week. That was just under $70 an hour. The electric costs for the main building and studios added to that. We had a ten ton AC just for six relay racks of video tape, and the master video processing system. You have no clue about the actual costs to maintain any Broadcast facility. The tower cost alone, was over a million dollars to build.

 

[Ricky C]

On Thursday, April 2, 2020 at 9:50:20 PM UTC-4, Phil Allison wrote:

Ricky Cretin is Absurd wrote:


---------------------------
On 2020-04-02 10:21, John Larkin wrote:


50 kilowatts of radiated RF must be expensive. 5G will probably take
over everything at a huge energy saving.


Larkin is funny. Talk about math challenged... 50 kW radiated is around $0.25 per hour. Factor of 2 from efficiency issues - hell make it 4 - gives $1 per hour.



** Really?

In the USA, domestic power cost about 12c per kWH

I expect a big user would get a discount, say to 10c per kWH

50 x 10 = 500 or $5.

If the power company can sell me power at $0.08/kWh I think they can sell it to a mass user at a better rate. In fact they can contract independently for the electricity generation and transmission and get that way down.

Even paying full retail rates, is $5/hr "expensive" for a commercial enterprise??? I guess that's why the big box stores turn off all their signs and lights at night. lol

Maybe that's why he doesn't seem to understand electric cars.


** Pot calls Kettle ??

" Tesla is not a brand, it's a Cult".

For some people. Other people just like driving electric cars with all the advantages they bring. Others rag about how they can't be driven in the winter or uphill without ever looking at any real data. Others yet just like to rag without having either an opinion or any knowledge on the topic.

You are like Larkin, a *nasty* piece of work. I'm surprised you haven't lit in with the profanities. Whatever. It's not like you had anything to say.

--

Rick C.

--- Get 1,000 miles of free Supercharging
--- Tesla referral code - https://ts.la/richard11209

 

[Ricky C]

On Thursday, April 2, 2020 at 9:53:11 PM UTC-4, whit3rd wrote:

On Thursday, April 2, 2020 at 6:29:51 PM UTC-7, Ricky C wrote:

Larkin is funny. Talk about math challenged... 50 kW radiated is around $0.25 per hour.

Huh? 50 kW radiated is close to $5 per hour around here. Heck, you could get
A PARKING SPOT DOWNTOWN with that much money.

Yeah, I dropped a decimal point. Here that wouldl be two parking spots!

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209

 

[Phil Allison]

Michael Terrell wrote:

----------------------

The electric bill for WACX TV in the late '80s was over $45,000 a month for their NTSC 130 KW Comark UHF transmitter. It was running at least 162 hours a week. That was just under $70 an hour.

** IOW absolute peanuts.

The receptionist plus coffee lady cost more in wages and overheads.



...... Phil

 

[Ricky C]

On Thursday, April 2, 2020 at 11:10:33 PM UTC-4, Michael Terrell wrote:

On Thursday, April 2, 2020 at 9:29:51 PM UTC-4, Ricky C wrote:
On Thursday, April 2, 2020 at 7:26:21 PM UTC-4, Joerg wrote:
On 2020-04-02 10:21, John Larkin wrote:
On Thu, 02 Apr 2020 09:32:36 +0300, upsidedown@downunder.com wrote:

On Wed, 1 Apr 2020 16:30:55 -0700 (PDT), Phil Allison
pallison49@gmail.com> wrote:

[...]

News to me.


... Phil

50 kilowatts of radiated RF must be expensive. 5G will probably take
over everything at a huge energy saving.


No, it's just that the energy then comes out of the bank account of the
recipient, to pay for the pricey cell package. And where I was today 5G
would not have reached anyhow (access only on foot, via mountain bike or
on a horse).

I don't know what the big deal is about 5G. It is faster cell phone service so that in dense cities you can pay the cell phone companies for all your data needs rather than paying the "cable" companies for the same thing.. I suppose some people watch movies on their cell phone, but really? It's not really anything you can't get now, except it will be from the cell companies instead of the cable companies.

Larkin is funny. Talk about math challenged... 50 kW radiated is around $0.25 per hour. Factor of 2 from efficiency issues - hell make it 4 - gives $1 per hour. Maybe that's why he doesn't seem to understand electric cars. He can't even do the math of how cheap they are to run. I wonder if he ever looks at the electric bill from his business.

The electric bill for WACX TV in the late '80s was over $45,000 a month for their NTSC 130 KW Comark UHF transmitter. It was running at least 162 hours a week. That was just under $70 an hour. The electric costs for the main building and studios added to that. We had a ten ton AC just for six relay racks of video tape, and the master video processing system. You have no clue about the actual costs to maintain any Broadcast facility. The tower cost alone, was over a million dollars to build.

You didn't grasp the problem. Larkin was talking about the power used to transmit the signal. It doesn't matter how you transmit the images, they still have to be made and distributed. It's just the transmitted signal that changes, wifi distributed all over a city with hundreds or thousands of small devices or one large transmitter. It's not rocket science, but Larkin doesn't like math. He picked a large number and ran with it.

Maybe it's not math he has trouble with but actually just understanding numbers. I guess he likes Spice because it provides pretty pictures.

--

Rick C.

-+- Get 1,000 miles of free Supercharging
-+- Tesla referral code - https://ts.la/richard11209

 

[Ricky C]

On Thursday, April 2, 2020 at 11:58:32 PM UTC-4, Michael Terrell wrote:

You didn't grasp the problem. Larkin was talking about the power used to transmit the signal. It doesn't matter how you transmit the images, they still have to be made and distributed. It's just the transmitted signal that changes, wifi distributed all over a city with hundreds or thousands of small devices or one large transmitter. It's not rocket science, but Larkin doesn't like math. He picked a large number and ran with it.

Maybe it's not math he has trouble with but actually just understanding numbers. I guess he likes Spice because it provides pretty pictures.


You never grasp anything, you just change the subject rather than admit your incompetence.

Sorry, that is the subject. No one ever said anything about running a radio station. Only powering a 50 kW signal. I figured there would be some large efficiency losses, but that wasn't what Larkin was talking about.

Go back and read the posts. Larkin said, "50 kilowatts of radiated RF must be expensive. 5G will probably take
over everything at a huge energy saving."

That was his entire post. Not the station, not even the transmitter, the "radiated RF".

So did I change the topic?

--

Rick C.

-++ Get 1,000 miles of free Supercharging
-++ Tesla referral code - https://ts.la/richard11209

 

[Michael Terrell]

You didn't grasp the problem. Larkin was talking about the power used to transmit the signal. It doesn't matter how you transmit the images, they still have to be made and distributed. It's just the transmitted signal that changes, wifi distributed all over a city with hundreds or thousands of small devices or one large transmitter. It's not rocket science, but Larkin doesn't like math. He picked a large number and ran with it.

Maybe it's not math he has trouble with but actually just understanding numbers. I guess he likes Spice because it provides pretty pictures.

You never grasp anything, you just change the subject rather than admit your incompetence.