¿ªÔÆÌåÓý

  1. Tinysa
  2. Messages
Expanded Topics Messages Polls
Date
Re: What accessories do I need for a TinySA Ultra?

 

Dave, W0LEV, is correct. The metric prefixes are well-defined. See?


for a list of them. One of the ones that people screw up is milli (m) vs. mega (M). When mHz (or mhz) is typed instead of MHz, most of us can infer the correct prefix and unit. But in actual scientific and engineering work, accuracy in notation is very important, so we strive to use the correct notation. The difference between milli (m) and mega (M) is *nine* (10E9) orders of magnitude.

The unit abbreviation is also screwed up by many people. The unit "Hertz" is properly abbreviated as "Hz" and not "hz" and named after Heinrich Hertz, who was the first physicist to prove the existence of electromagnetic waves after Maxwell predicted them mathematically. We pay tribute to Hertz's pioneering work by capitalizing the abbreviation Hz. Other examples are J for Joule, W for Watt, O for Oersted, T for Telsa (the physicist, not the vehicle), V for volt, etc., etc., all named after the scientists who first discovered or identified the quantity in question. While many users of the tinysa are not engineers by vocation, they have to know or learn the technical principles involved with using spec ans and it behooves us (at least IMHO) to get the notation correct when communicating technical information.

There are other units the abbreviations for which people routinely mistype. The difference between "S" (Siemens) and "s" (seconds) comes to mind.

One of the basic techniques for solving mathematical equations in scientific work is to perform unit analysis as well as the mathematical calculation. Unit analysis involves ignoring the numbers and looking at the units to make sure that the units agree on both sides of the equation. If one starts with something such as "Volts/meter" on the LH side of the equation and unit analysis results in "meters/second" on the RH side of the calculation, one knows that one has miscalculated. Using the correct abbreviations for the units involved is key to accomplishing that effort.

The above is just my take on this stuff after working for 30+ years as an embedded systems design engineer in the IBM computer world of engineering. Worth 25 cents, taking into account inflation.

DaveD
KC0WJN


On Fri, May 16, 2025 at 20:16 Mike C. via <mg=[email protected]> wrote:

Hate to burst your bubble Dave, but the HP-3561A , in their documentation, refers to the low frequency coverage (micro Hz) as uHz, and how about kHz. So, yeah, mHz for "mili Hz" works for me but hey I'm only a retired technician. BTW electron flow is from (-) negative to (+) positive, but the engineers I worked with called it "hole flow". ??? I guess they stand on an overhead bridge and watch the spaces going the opposite way than the cars.

Clip from pdf of HP's 3561A:

Just sayin'

Mike C. Sand Mtn GA


On 5/16/2025 6:34 PM, W0LEV via wrote:
Yea, Don, get the newbies to use proper abbreviations!? I've called it out many times, but it seems to fall on deaf ears and clearly never reaches the gray matter.? What really gets my goat is "mhz".? What is mhz?? MilliHertz?? Nothing the typical amateur deals with delves into the milliHertz range!? Further the proper abbreviation for Hertz is Hz, not hz!? Should I give up?

Dave - W?LEV

On Fri, May 16, 2025 at 5:49?PM Donald S Brant Jr via <dsbrantjr=[email protected]> wrote:
On Thu, Mar 20, 2025 at 04:17 PM, sdegroff wrote:
All references when not given are 0db = 1w
My observation is that very few people use units of dbW even when working at high power, dbm (relative to 1 milliwatt) being far more common.?
If a colleague started using dBW I would ask them why as I see no good reason for it, it is likely to cause confusion.? Like 1000X level confusion.
?
In the RF world, if something is written as "xdB" it is NOT a power level, it is a power ratio, or actually 10log of that ratio.?
?
The TinySA power specs all use dBm AFAIK.
73, Don N2VGU


--
Dave - W?LEV
Re: What accessories do I need for a TinySA Ultra?

 

Yes, I have one generator that goes to ?Hz.? But I'm not a typical ham by any means!? If you build yourself a seismometer, you're in the mHz region.

Dave - W?LEV

On Sat, May 17, 2025 at 12:16?AM Mike C. via <mg=[email protected]> wrote:

Hate to burst your bubble Dave, but the HP-3561A , in their documentation, refers to the low frequency coverage (micro Hz) as uHz, and how about kHz. So, yeah, mHz for "mili Hz" works for me but hey I'm only a retired technician. BTW electron flow is from (-) negative to (+) positive, but the engineers I worked with called it "hole flow". ??? I guess they stand on an overhead bridge and watch the spaces going the opposite way than the cars.

Clip from pdf of HP's 3561A:

Just sayin'

Mike C. Sand Mtn GA


On 5/16/2025 6:34 PM, W0LEV via wrote:
Yea, Don, get the newbies to use proper abbreviations!? I've called it out many times, but it seems to fall on deaf ears and clearly never reaches the gray matter.? What really gets my goat is "mhz".? What is mhz?? MilliHertz?? Nothing the typical amateur deals with delves into the milliHertz range!? Further the proper abbreviation for Hertz is Hz, not hz!? Should I give up?

Dave - W?LEV

On Fri, May 16, 2025 at 5:49?PM Donald S Brant Jr via <dsbrantjr=[email protected]> wrote:
On Thu, Mar 20, 2025 at 04:17 PM, sdegroff wrote:
All references when not given are 0db = 1w
My observation is that very few people use units of dbW even when working at high power, dbm (relative to 1 milliwatt) being far more common.?
If a colleague started using dBW I would ask them why as I see no good reason for it, it is likely to cause confusion.? Like 1000X level confusion.
?
In the RF world, if something is written as "xdB" it is NOT a power level, it is a power ratio, or actually 10log of that ratio.?
?
The TinySA power specs all use dBm AFAIK.
73, Don N2VGU


--
Dave - W?LEV




--
Dave - W?LEV
Re: What accessories do I need for a TinySA Ultra?

 

¿ªÔÆÌåÓý

Hate to burst your bubble Dave, but the HP-3561A , in their documentation, refers to the low frequency coverage (micro Hz) as uHz, and how about kHz. So, yeah, mHz for "mili Hz" works for me but hey I'm only a retired technician. BTW electron flow is from (-) negative to (+) positive, but the engineers I worked with called it "hole flow". ??? I guess they stand on an overhead bridge and watch the spaces going the opposite way than the cars.

Clip from pdf of HP's 3561A:

Just sayin'

Mike C. Sand Mtn GA


On 5/16/2025 6:34 PM, W0LEV via groups.io wrote:

Yea, Don, get the newbies to use proper abbreviations!? I've called it out many times, but it seems to fall on deaf ears and clearly never reaches the gray matter.? What really gets my goat is "mhz".? What is mhz?? MilliHertz?? Nothing the typical amateur deals with delves into the milliHertz range!? Further the proper abbreviation for Hertz is Hz, not hz!? Should I give up?

Dave - W?LEV

On Fri, May 16, 2025 at 5:49?PM Donald S Brant Jr via <dsbrantjr=[email protected]> wrote:
On Thu, Mar 20, 2025 at 04:17 PM, sdegroff wrote:
All references when not given are 0db = 1w
My observation is that very few people use units of dbW even when working at high power, dbm (relative to 1 milliwatt) being far more common.?
If a colleague started using dBW I would ask them why as I see no good reason for it, it is likely to cause confusion.? Like 1000X level confusion.
?
In the RF world, if something is written as "xdB" it is NOT a power level, it is a power ratio, or actually 10log of that ratio.?
?
The TinySA power specs all use dBm AFAIK.
73, Don N2VGU


--
Dave - W?LEV
Re: What accessories do I need for a TinySA Ultra?

 

Yea, Don, get the newbies to use proper abbreviations!? I've called it out many times, but it seems to fall on deaf ears and clearly never reaches the gray matter.? What really gets my goat is "mhz".? What is mhz?? MilliHertz?? Nothing the typical amateur deals with delves into the milliHertz range!? Further the proper abbreviation for Hertz is Hz, not hz!? Should I give up?

Dave - W?LEV

On Fri, May 16, 2025 at 5:49?PM Donald S Brant Jr via <dsbrantjr=[email protected]> wrote:
On Thu, Mar 20, 2025 at 04:17 PM, sdegroff wrote:
All references when not given are 0db = 1w
My observation is that very few people use units of dbW even when working at high power, dbm (relative to 1 milliwatt) being far more common.?
If a colleague started using dBW I would ask them why as I see no good reason for it, it is likely to cause confusion.? Like 1000X level confusion.
?
In the RF world, if something is written as "xdB" it is NOT a power level, it is a power ratio, or actually 10log of that ratio.?
?
The TinySA power specs all use dBm AFAIK.
73, Don N2VGU



--
Dave - W?LEV
Re: What accessories do I need for a TinySA Ultra?

 

¿ªÔÆÌåÓý

One word. MOVE.

Mike C. Sand Mtn GA

PS Better yet, drop a #10 gauge wire straight out your window, shove it into the ground (bare) then connect the other end, 'CAREFULLY', to your ground lug on the outlet but quickly disconnect it if the building catches fire.


On 5/16/2025 2:04 PM, Adam Coate via groups.io wrote:

I am very unfortunate in that my townhouse has both dirty electricity and dirty ground in the outlets. I had been using grounding mats/ sheets in my bed. After some testing I found out that current was actually flowing through the ground plug and into the grounding mat. Our townhouses were built in 1962 and don't appear to have an electrode grounding system. They're using the copper water pipes as the ground and so they're also conducting stray voltage back into the house via the water main.?
?
Anyway, what can I do to discharge the voltage built up in my 3 foot SMA cable and HTOOL HT8 log periodic antenna? Grounding rod??
Re: What accessories do I need for a TinySA Ultra?

 

I am very unfortunate in that my townhouse has both dirty electricity and dirty ground in the outlets. I had been using grounding mats/ sheets in my bed. After some testing I found out that current was actually flowing through the ground plug and into the grounding mat. Our townhouses were built in 1962 and don't appear to have an electrode grounding system. They're using the copper water pipes as the ground and so they're also conducting stray voltage back into the house via the water main.?
?
Anyway, what can I do to discharge the voltage built up in my 3 foot SMA cable and HTOOL HT8 log periodic antenna? Grounding rod??
Re: What accessories do I need for a TinySA Ultra?

 

¿ªÔÆÌåÓý

I can attest to that for sure (discharging cables). As a lead tech, working for uncle sugar many years ago at NNSY (Norfolk Naval Shipyard), I was assigned to re hook-up a long wire antenna on top of bldg. 510 on a very dry day. I instructed my assistant NOT to touch the down-lead of the antenna but to short it to GROUND first. I then turned to another task only to hear lots of 'expletives' filling the air. Turning back to my assistant I asked what happened only to see him throw the down-lead away from himself.

I then 'snarkily' asked him if he had touched the down-lead to which he replied, "yes." I then answered his puzzled look by pointing to the 'long-wire' above and informing him of a slight breeze for the 'discomfort' he had experienced. I believe he learned a very valuable lesson without being seriously hurt (except for his pride). End of conversation.

Mike C. Sand Mtn GA


On 5/16/2025 1:22 PM, Donald S Brant Jr via groups.io wrote:

One of the best things you can do to prevent ESD failures is to develop a habit of discharging any cable before you mate it with any kind of equipment.? Cables can acquire a many-thousand volts charge by bending, handling or unrolling them, as well as by being attached to an ungrounded antenna, and hold it for a surprisingly long time.??
Simply shorting inner and outer conductors with the outer conductor of the mating connector is sufficient and will go a long way towards protecting your equipment.? Get into the habit of doing this EVERY time.
73, Don N2VGU
Re: What accessories do I need for a TinySA Ultra?

 

On Thu, Mar 20, 2025 at 04:17 PM, sdegroff wrote:
All references when not given are 0db = 1w
My observation is that very few people use units of dbW even when working at high power, dbm (relative to 1 milliwatt) being far more common.?
If a colleague started using dBW I would ask them why as I see no good reason for it, it is likely to cause confusion.? Like 1000X level confusion.
?
In the RF world, if something is written as "xdB" it is NOT a power level, it is a power ratio, or actually 10log of that ratio.?
?
The TinySA power specs all use dBm AFAIK.
73, Don N2VGU
Re: What accessories do I need for a TinySA Ultra?

 

One of the best things you can do to prevent ESD failures is to develop a habit of discharging any cable before you mate it with any kind of equipment.? Cables can acquire a many-thousand volts charge by bending, handling or unrolling them, as well as by being attached to an ungrounded antenna, and hold it for a surprisingly long time.??
Simply shorting inner and outer conductors with the outer conductor of the mating connector is sufficient and will go a long way towards protecting your equipment.? Get into the habit of doing this EVERY time.
73, Don N2VGU
Re: What accessories do I need for a TinySA Ultra?

 

Unless an input or output is marked, as happens with some very high-power attenuators, I assume they are bidirectional.? They are generally Pi or T topology and thus symmetrical.
A notable exception, which are also clearly marked and may have mismatched connectors (commonly SMA on the 50 ¦¸ end and type F on the other), are 50¦¸ to 75¦¸ minimum loss pads, which have an L topology and are definitely asymmetrical.
73, Don N2VGU
?
Re: True frequency band upper limit detection level of TinySA Ultra ZS-407 and corresponding signal dropoff

 

Agree, but not everybody has such a sensor
--
Designer of the tinySA
For more info go to

Re: True frequency band upper limit detection level of TinySA Ultra ZS-407 and corresponding signal dropoff

 

On Thu, May 15, 2025 at 10:03 AM, Erik Kaashoek wrote:
Doing a full band scan (zero to max frequency) will also work.
M preferred method of dealing with an unknown signal is by using a wideband power sensor and slowly approaching the mating connector with the unknown signal, I can sense a whopping signal by capacitive coupling before full engagement and adjust the external attenuation appropriately; sweeping a SA full band takes some time and might miss something important until it is too late.
Best regards, Don Brant
Re: Hunting Spurious Emission at 154 MHz

 

No special settings. Center the sweep frequency in the center of the QRM with minimum span to cover the unwanted signal. RBW should be on auto. Narrow the span tightly on one spike if the signal is complex and broad. Enable waterfall to more easily see signal strength changes. Make sure LNA is off and possibly add attenuation if needed as you near the source.
?
Holding the SA close to your stomach while doing a slow 360 turn should give you a null or dip when the source is behind you depending on frequency.
?
Good luck hunting!
Re: What accessories do I need for a TinySA Ultra?

 

Bruce Akhusrst, Roger Hartel:
?
Thank you.
Of course they came from AliExpress. Anyway, they are working and I can use them for my humble needs.
Neither the seller (except one!) nor the manufacturer's website datasheets stated that the male plug end is the input for the 10 watt attenuator.?
Re: What accessories do I need for a TinySA Ultra?

 

Quite a lot of cheap (and not so cheap) low power chinese attenuators DO declare an input side in datasheets.? ?This is not done for fun.? ? ? It is almost always the male plug side that is declared as input.

Only Extremely expensive high power attenuators are two way? ? All the others DO have an input side and again if so it's usually the male plug end that is input (i.e has a high power resistor at that end )
Re: What accessories do I need for a TinySA Ultra?

 

No


On Thu, May 15, 2025, 2:04?PM Wlado, D2CR via <dogbit7=[email protected]> wrote:
Hi,
Does it matter which side of the attenuators to connect (as in the photo) if there is no input/output marking?
Thanks in advance.
Wlado
Re: What accessories do I need for a TinySA Ultra?

 

Hi,
Does it matter which side of the attenuators to connect (as in the photo) if there is no input/output marking?
Thanks in advance.
Wlado

att2w.png
att10w.png

Re: True frequency band upper limit detection level of TinySA Ultra ZS-407 and corresponding signal dropoff

 

On Thu, May 15, 2025 at 05:40 AM, Donald S Brant Jr wrote:
It is good practice to check the power of an unknown source with a wideband power sensor.?
Doing a full band scan (zero to max frequency) will also work.
--
Designer of the tinySA
For more info go to

Re: True frequency band upper limit detection level of TinySA Ultra ZS-407 and corresponding signal dropoff

 

On Wed, May 14, 2025 at 07:26 AM, Adam Coate wrote:
what actual signal strength (in dBm) causes the device to enter Overload mode
Remember, it is the total power going into the mixer or ADC which can cause an overload indication, not just the signals being displayed on the screen.??
It is good practice to check the power of an unknown source with a wideband power sensor.??
Appropriate high-, low- or bandpass filtering can also be helpful, not just for overload prevention but to avoid images/mirroring in Ultra mode.
73, Don N2VGU
Re: Wideband spurious signal?

 

Thanks David and Erik.
?
I find cell tower signals that look similar in lower frequency ranges, that are plausible cell tower signals, e.g. LTE band 1 downlink (20 MHz):
?
They also match the german frequency plan:
?
The signal i've mentioned in the 8.56 GHz range is one of the strongest signal i can find on the whole range up to 9 GHz (even stronger than the local FM radio tower), see here:
?
Another signal around 7.5 Ghz is also very strong. I've now attached an 6dB attenuator to be sure to not blow out the LNA.
?
Comparing the LTE signal with the 8.56 GHz signal, i find it looks very similar. The bandwidth is just higher with 60 MHz vs. the 20 MHz LTE signal.
So it doesn't seem to be a mirror of another signal in the lower ranges, because i can't find anything with the same bandwidth and/or power.
?
I find it very odd, because in the frequency plan, the only signal in the 8400 to 8500 MHz range is "permanent radio service", which sounds plausible.
The thing is, the signal goes from 8.47 GHz to 8.53 GHz - so it overlaps.
?
I monitored the signal (late evening into the night), and to me, it doesn't look like a cell tower signal:
The signal suddenly stops in the middle of the day for some time, and the power level drops abruptly going into the night.
?
Comparing that to a real LTE signal (band 20), the difference can be seen:
Gradual power level changes over time (evening over night to morning) with abrupt increases due to transmissions. But never does the signal suddenly disappear.
?
I think i will invest in a high pass filter to be sure i'm not hunting ghosts.
101 - 120 of 19811