Undamped meter, just for fun.

[Jan Panteltje]

On a sunny day (Mon, 12 Aug 2019 10:30:50 -0700) it happened John Larkin
<jjlarkin@highlandtechnology.com> wrote in
<cb83le5f2jv9s1d5p701c1nmr9mv2lmbcj@4ax.com>:

On Mon, 12 Aug 2019 09:35:46 -0700 (PDT), amdx62@gmail.com wrote:

On Monday, August 12, 2019 at 11:30:46 AM UTC-5, Rick C wrote:
On Monday, August 12, 2019 at 11:53:01 AM UTC-4, John Larkin wrote:
On Sun, 11 Aug 2019 12:47:22 -0500, amdx <nojunk@knology.net> wrote:

I was measuring the internal resistance of a D'arsovnal meter.
When I connected my PS, the meter started oscillating, I quickly
disconnected my PS and checked it, it seemed fine.
I reconnected the PS, and just let it oscillate until it stopped.
So I made a video 28V, 400k ohm series resistor and the meter,
The spec's, 55 ohms internal resistance and 124uA FS.
No big deal, just never saw a meter swing so much. Yes, I went high
series resistance to maximize the oscillation. No, I don't have a
parallel resistor to dampen it.

https://www.youtube.com/watch?v=1IsH6S2TK7w


Mikek





Is there an optimal resistor source impedance for best damping?

Yes, of course. It's called critical damping. I would expect you to know about this since there is an analog in filter
design.

--

Rick C.

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

I suspect he did, maybe some Socratic teaching.

The question was sincere.

Naming something "critical damping" is not the answer.

I suppose it's even possible that the optimum damping resistor could
be negative.

Think about it, if you want to stop a generator,
don't you think the lower the shorting resistance the more it breaks?
So, short it.
Negative where is that for sale?

 

[Jan Panteltje]

<nojunk@knology.net> wrote

On 8/12/2019 12:07 PM, Jan Panteltje wrote:
On a sunny day (Mon, 12 Aug 2019 11:24:40 -0500) it happened amdx
nojunk@knology.net> wrote in <qis3s6$gm5$1@dont-email.me>:

I might add, before I look at super-heterodyne receivers, I have this
on my agenda.
https://forums.qrz.com/index.php?threads/feedback-on-building-a-bog-antenna.669192/

Mikek

I do not make deals,

That's OK, it wasn't expected, it was more of a I'm pulling your leg,
type line.

I don't know what it is that you posted. Is it a glorified Firestick?

No idea what a firestick it (some sort of ancient lighter I presume ;-)


>Is it an over the air tuner and recorder? Is it a combination of both?

It is a DVB-T2 digital terrestrial radio and TV tuner, recorder too if you plug a USB stick in it
plus it can show youtube in HD (if you connect it to a LAN).
read the description in the link:
https://www.ebay.com/itm/173920120323

Not sure it is of use to 'merricans, maybe those do not have DVB-T2 or use other frequencies or whatever.

Terrestrial transmissions here are at:
https://radio-tv-nederland.nl/dvbt/digitenne-kpntv.html
look under MHz.

The BOG is an antenna for AM BCB, 160M, 80M, and 40M radio signals.
It takes up 260 linear ft x 1/16 inch and several square inches at
each end!

Yea, not enough space here.
Anyways I have done AM rx when I was very very young using my metal bed spiral as antenna
secretly listening with my crystal radio at night to radio plays...
Most AM transmitters are now turned off here I think?
I have done 40 M and shorter as radio ham, have a nice antenna tuner so the antenna matching
is never a problem can even match it to a metal fence if it must be.
For the shortwave bands there are those small active things, see below at end of posting,
Anyways DX? we have QO100 satellite now, most of Europe Asia, Middle East and some Brasil
via satellite with signal as clear as local FM, including amateur digital TV, web receiver here:
https://eshail.batc.org.uk/
with just a satellite dish.
I have several shortwave receivers, SSB too, not much to hear on those band you describe
some Chinese stations transmitting in English, is BBC still there?
Weaterfax on long wave, why make it so hard on yourself,
I took down my 27 MHz / 10 m GPA long ago,

I am just waiting for a better low noise (Dr. Phil is working on that if I understand it right) receiver
to watch the alien TV channels to see what is going on there.
But more seriously those longer wave bands are severely polluted by our modern switch mode super efficient
gadgets,,,

My DVB-T2 antenna is just a lemme see 10 cm (4 inches for the eeeh UK???) thing with magnetic base,
For digital TV I put it in the window for better reception.

These sort of receive antennas for the shortwave seem to work well, need to try one one day,
but too much noise here:
http://www.pa3fwm.nl/projects/miniwhip/

You can listen to it on the web-sdr here:
http://websdr.ewi.utwente.nl:8901/

There is no end to what can be written on the subject, better stop here.

2 meter and 70 cm is still mainly noise free here,

 

[Rick C]

On Monday, August 12, 2019 at 2:54:01 PM UTC-4, Jan Panteltje wrote:

On a sunny day (Mon, 12 Aug 2019 10:30:50 -0700) it happened John Larkin
jjlarkin@highlandtechnology.com> wrote in
cb83le5f2jv9s1d5p701c1nmr9mv2lmbcj@4ax.com>:

On Mon, 12 Aug 2019 09:35:46 -0700 (PDT), amdx62@gmail.com wrote:

On Monday, August 12, 2019 at 11:30:46 AM UTC-5, Rick C wrote:
On Monday, August 12, 2019 at 11:53:01 AM UTC-4, John Larkin wrote:
On Sun, 11 Aug 2019 12:47:22 -0500, amdx <nojunk@knology.net> wrote:

I was measuring the internal resistance of a D'arsovnal meter.
When I connected my PS, the meter started oscillating, I quickly
disconnected my PS and checked it, it seemed fine.
I reconnected the PS, and just let it oscillate until it stopped.
So I made a video 28V, 400k ohm series resistor and the meter,
The spec's, 55 ohms internal resistance and 124uA FS.
No big deal, just never saw a meter swing so much. Yes, I went high
series resistance to maximize the oscillation. No, I don't have a
parallel resistor to dampen it.

https://www.youtube.com/watch?v=1IsH6S2TK7w


Mikek





Is there an optimal resistor source impedance for best damping?

Yes, of course. It's called critical damping. I would expect you to know about this since there is an analog in filter
design.

--

Rick C.

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

I suspect he did, maybe some Socratic teaching.

The question was sincere.

Naming something "critical damping" is not the answer.

I suppose it's even possible that the optimum damping resistor could
be negative.

Think about it, if you want to stop a generator,
don't you think the lower the shorting resistance the more it breaks?
So, short it.

Wouldn't it be best to match the impedance for maximum power transfer?

--

Rick C.

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

 

понеділок, 12 серпня 2019 р. 20:23:32 UTC+3 користувач amdx написав:

On 8/12/2019 12:07 PM, Jan Panteltje wrote:
On a sunny day (Mon, 12 Aug 2019 11:24:40 -0500) it happened amdx
nojunk@knology.net> wrote in <qis3s6$gm5$1@dont-email.me>:

I might add, before I look at super-heterodyne receivers, I have this
on my agenda.
https://forums.qrz.com/index.php?threads/feedback-on-building-a-bog-antenna.669192/

Mikek

I do not make deals,

That's OK, it wasn't expected, it was more of a I'm pulling your leg,
type line.

I don't know what it is that you posted. Is it a glorified Firestick?
Is it an over the air tuner and recorder? Is it a combination of both?


The BOG is an antenna for AM BCB, 160M, 80M, and 40M radio signals.
It takes up 260 linear ft x 1/16 inch and several square inches at
each end!
Mikek



but I have a small DVB-T antenna and a bought new DVB-T2 tuner
as the system here moved to DVB-T2:
https://www.ebay.com/itm/173920120323
gets several channels in HD

General
Complete name : tv_noord_ffmpeg_vcodec_copy.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom
File size : 86.6 MiB
Duration : 3mn 19s
Overall bit rate : 3 638 Kbps
Writing application : Lavf57.56.101

Video
ID : 1
Format : hev1
Codec ID : hev1
Duration : 3mn 19s
Bit rate mode : Variable
Bit rate : 3 502 Kbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16/9
Frame rate mode : Constant
Frame rate : 50.000 fps
Bits/(Pixel*Frame) : 0.034
Stream size : 83.3 MiB (96%)

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format version : Version 4
Format profile : LC
Format settings, SBR : No
Codec ID : 40
Duration : 3mn 19s
Bit rate mode : Constant
Bit rate : 129 Kbps
Channel(s) : 2 channels
Channel positions : L R
Sampling rate : 48.0 KHz
Resolution : 16 bits
Stream size : 3.08 MiB (4%)
Language : Dutch


Not bad for 23$90 free shipping
Strongly recommended, can set timers too, works on mains and also on 5V..

So what can you receive on your 'bog' antenna and how much space does that take and what does it cost including the receiver?
This is 2019

Satellite dishes are even better.
Sat boxes are just as cheap.

Do not hang in the past, it no longer exists,

As for me, I really like Firestick a lot, it is a great device. I have installed a lot of cool apps on it using the guides from https://www.firestickhow.com/kodi-addons.html and I like it so much! I recommend that you check that resource too, you will like it surely

 

As for me, I really like Firestick a lot, it is a great device. I have installed a lot of cool apps on it using the guides from https://www.firestickhow.com/kodi-addons.html and I like it so much! I recommend that you check that resource too, you will like it surely