Re: I originally asked: good source & non-expensive url for Attenuators
On Thu, Jan 14, 2021 at 11:37 AM, wb6ogd wrote:
Don't you have enough RF in your shack that you could just us the tinySA antenna
to get enough signal to check it?
Garry, yes and now, depends what you are measuring. If you just want to see signal around the carrier (for example you CW, or how wide is your SSB, or how deep is modulation on AM, or haw flat you FM), then you are right. I need it to measure harmonic distortions - emissions on multiples of the base frequency, and getting signal from "the air around" brings all random attenuations on different frequencies (transmitting antenna, walls, tinySA antenna, ... Much (MUCH) more deterministic with "physical"? tap?
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Re: I originally asked: good source & non-expensive url for Attenuators
<bammi asked> Do you have an opinion about a tap as you suggest vs. sampling the signal. That question was recently asked in another thread, not many responses, but among ones that did respond I'd say that:
- resistive
- easier/cheaper for DIY
- if you use quality resistors (low inductance) and if you have good way to test transfer function (nanoVNA for example) to do some fine tuning, can get wider and flatter frequency response
- inductive
- half way to building SWR meter :)
- IMHO looks cooler :)
- the key benefit - galvanic isolation (high voltage DC on the coax/antenna/TX side won't "traverse" the current transformer
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Instead of these savers, why not use little SMA pigtails (6" or so)?
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I bought mine from W5SWL. USA seller, fast shipping, decent products. He sells direct or eBay. 73 -Jim NU0C On Fri, 15 Jan 2021 15:09:56 -0800 "Roger Need via groups.io" <sailtamarack@...> wrote: The SMA connectors on the TinySA? were never meant for hundreds of connect/disconnects and will wear out eventually especially if the center pin is allowed to rotate and "drill out" the SMA jack. A good way to protect your device is to use "connector savers". Once they wear out you simply replace them with new ones. There are several places you can buy them online. I purchased mine on eBay from a Chinese seller for about 8 USD (including shipping).
I bought mine here ...
;var=464095337588&_trksid=p2057872.m2749.l2649
If you want better quality (Amphenol) and 2 day delivery order from Digi-Key ....
Roger
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The SMA connectors on the TinySA? were never meant for hundreds of connect/disconnects and will wear out eventually especially if the center pin is allowed to rotate and "drill out" the SMA jack. A good way to protect your device is to use "connector savers". Once they wear out you simply replace them with new ones. There are several places you can buy them online. I purchased mine on eBay from a Chinese seller for about 8 USD (including shipping).
I bought mine here ...
;var=464095337588&_trksid=p2057872.m2749.l2649
If you want better quality (Amphenol) and 2 day delivery order from Digi-Key ....
Roger 
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Re: I originally asked: good source & non-expensive url for Attenuators
Thanks for the response Miro. I came across Don Jackson's article after I posted my remarks. A similar well thought out design for a high power rf sampler can be found in the May 2011 issue of QST on pages 52 and 53 in the Technical Correspondence section by Tom Thompson, W0IVJ.
The two couplers shown on Frank Dorenberg's page, N4SSP, that I previously posted probably would not work well at higher frequencies
because they neglected to include a faraday shield to prevent capacitive coupling to the?secondary winding and they also neglected to put a shunt?resistor on the secondary. I'd already seen the g3yhn.info pages.
It all depends on what your trying to do and what your trying to measure. As has been already mentioned, if you're just trying to measure relative levels and not absolute values you could just?use the tinySA antenna.
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I had the same problem.
You may need to manually update the device drivers for the ST DFU Se Demo program.
Look in device manager for that device and update the drivers by pointing to the top level directory where the program is installed including the sub-directories.?? There is also a previous post on this issue.
Your computer may reboot to install these drivers and then the firmware update can proceed using the ST DFU program.
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I used to be able to program firmware for NanoVNA and TinySA on my main computer but after installing the STM Cube IDE and Cube Programmer, neither is recognized when set to DFU mode. Works fine for normal connection though. I put DFUseDemo and driver on a laptop and can program from there.
Gary
W9TD
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Ed, I had a problem with my Dell i5 W10 64bit computer using DfuSe, it would not update either of my TinySA's and in trying to force them I ended?up with a white screen on both. I then downloaded STCube, it's a much easier program to use for updating the firmware. However, that being said, I still had a problem, re-loading and updating the software still failed.
In desperation I loaded STCube onto an older Toshiba i3 W10 computer and it reloaded the firmware on both TinySA's without issue. I then tried to update to the latest firmware on the Dell, it failed, I then loaded STCube onto an Acer i3 W10 tablet and updated the firmware and it worked flawlessly.
This led me on a several hour long investigation as to why it failed. Turned out that on the Dell the program could not recognize the ST and that prevented the program from loading the chip profile from the STCube database which is needed to update the firmware, the other computers had no issue and the chip type showed up in the information panel.
I have no idea why the Dell failed but the Toshiba and Acer worked without issue, I tried the 2.0 and 3.0 USB ports and different cables on the Dell but none worked. I suggest you try STCube and look to see if the program is detecting your TinySA chip designator.
Hope this was helpful. Greg.M
I am not sure what is going on here. I was originally having trouble connecting with the TinySA on my primary ham radio computer and took it over to another computer and had success. I went back to the first computer and reduced the number of transmit and receive buffers in the USB serial device driver and then had success on the first computer. The next day, I was back to square one with the TinySA app on both computers. I also was not able to see the TinySA in DfuSeDemo on either computer. Both computers are older systems running 32-bit Windows 10.
I then installed the DfuSeDemo application and the firmware update on a newer 64-bit Windows 10 computer and was able to update the firmware successfully. I also had no problems with the TinySA app on this newer computer. Apparently then the USB cable and connectors are OK as is the TinySA itself (it passed the self-test before and after the firmware update). The two older 32-bit computers are current with Windows 10 updates.
Again, thanks in advance for any ideas.
Ed, K0KC
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I am not sure what is going on here. I was originally having trouble connecting with the TinySA on my primary ham radio computer and took it over to another computer and had success. I went back to the first computer and reduced the number of transmit and receive buffers in the USB serial device driver and then had success on the first computer. The next day, I was back to square one with the TinySA app on both computers. I also was not able to see the TinySA in DfuSeDemo on either computer. Both computers are older systems running 32-bit Windows 10.
I then installed the DfuSeDemo application and the firmware update on a newer 64-bit Windows 10 computer and was able to update the firmware successfully. I also had no problems with the TinySA app on this newer computer. Apparently then the USB cable and connectors are OK as is the TinySA itself (it passed the self-test before and after the firmware update). The two older 32-bit computers are current with Windows 10 updates.
Again, thanks in advance for any ideas.
Ed, K0KC
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Ed, K0KC
?
k0kc@...
http://k0kc.us/
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You can also try tinySA-App to do the FW update --
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For more info on the tinySA go to https://tinysa.org/wiki/
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I am unable to update the firmware on my TinySA using a DFU file or a bin file. The current firmware version on my TinySA is v1.1-12.
I have downloaded and installed the DfuSeDemo tool. When I place the TinySA in the DFU mode using the menu, nothing shows under the Available DFU Devices in the DfuSeDemo tool.
The bin approach to updating also failed because the .bat file indicated that dfu-util-static.exe was not compatible with Windows 10.
Thanks in advance for any assistance!
Ed, K0KC
k0kc@... http://k0kc.us/ --
Ed, K0KC
?
k0kc@...
http://k0kc.us/
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Re: There is a new firmware update for tinySA, version 1.1.74
The ?original announcement explains the modification(s) and can be found in the messages section ——> ? ? /g/tinysa/message/2680
On Thu, Jan 14, 2021 at 4:51 PM Julio Rosa < juliocsrs@...> wrote: There is a new firmware update for tinySA, version 1.1.74. Would anyone know what was modified in this new version? Thanks.
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Re: I originally asked: good source & non-expensive url for Attenuators
On Thu, Jan 14, 2021 at 11:27 AM, bammi wrote:
Do you have an opinion about a tap as you suggest vs. sampling the signal
My opinion is that it depends on what you are measuring ?I am not sure of the linearity of the antenna when spanning a hundred MHz. A direct tap frequency response can be measured with a VNA to validate there is no loss or gain as a result of the connection. ?The separate antenna could pick up other stray signals in the area and mix with the ones you are trying to measure ?
With the above said, most all needs of a ham could be done without the direct connection. Assuming you are not down to measuring less than 2 or 3 DB difference. This could be critical for the 3rd harmonic of some of the uBITX bands that should be verified before and after amplification.?
my opinion, so cold be in error.?
73
Evan
AC9TU
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Locked
Re: What to do when you think you bought a tinySA clone.
My previous comment may have been not clear. Feel free to share information about which sellers are selling clones but please do not share information on the mistakes the cloners made that allow us to recognize the clones except for sharing pictures. These picture help me to spot mistakes so I can tell you if a tinySA shown on the picture is a clone or note. Also please do not share technical information on how a clone should me "improved" as this is vital info for the cloners to make it impossible more difficult detect a clone On this wiki page I share all "public"? info on how to recognize a clone: https://tinysa.org/wiki/pmwiki.php?n=Main.Buying --
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For more info on the tinySA go to https://tinysa.org/wiki/
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Locked
Re: What to do when you think you bought a tinySA clone.
On 2021-01-14, at 11:26, Erik Kaashoek < erik@...> wrote:
Yes, the tinySA logo and the tinySA name for a spectrum analyzer are trademarked thus these are illegal?products.
Thanks; that is good to know.
The Banggood fake also fails self-test, see below.
Grü?e, Carsten
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Re: I originally asked: good source & non-expensive url for Attenuators
Dumb question here....
You guys are trying to check the output from your transmitter,
right?
Don't you have enough RF in your shack that you could just us the
tinySA antenna
to get enough signal to check it?? It is a form of inductive
coupling, no?
If you are checking a qrp rig, maybe wrap a wire around your dummy
load to get
more coupling.
73,
Gary
WB6OGD
On 1/14/2021 8:36 AM, Miro, N9LR via
groups.io wrote:
toggle quoted message
Show quoted text
Hi Dennis!
inductive coupler still requires dummy load, and if you have one,
then your resistive attenuator does not need "large power
absorbing resistors".
In another thread in this group someone posted this link to the
excellent article on theory and practice of inductive couplers ()
Article in your comment is quite misleading if not wrong -
inductive coupling is done by means of current transformer. If you
leave secondary side of current transformer "open" (no terminator
with resistor), in theory potential at it's ends will be infinite
value and in practice can reach thousands of volts!
Also, reflected impedance in primary will be quite high and will
cause significant voltage drop and dissipated power in turn.
Simply said, current transformer MUST be terminated on the
secondary side at all times!
The "fix" is surprisingly cheap and simple - just have properly
designed resistor :)
Also, number of turns and selection of toroid material is not a
random effort - just check the link above, and if you desire to
learn even more, check the link in that document that takes you
here?
I still don't know what are comparative advantages/disadvantages
of "resistive vs inductive" high impedance taps. Resistive are
easier to make and have wider bandwidth (when done correctly),
inductive gives you galvanic isolation, but not sure if there is
anything else.
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Re: I originally asked: good source & non-expensive url for Attenuators
Evan/Miro
Do you have an opinion about a tap as you suggest vs. sampling the signal. (few turns of wire around a through RF connection, and depending ?on the resultant Magnetic coupling inducing signal into the sampling loop)
I agree that direct attentuation does not make sense when any kind of power is involved.
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73 de k1jbd
bammi
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Jim Shorney
Roger Need
Gary W9TD
Brent DeWitt
WS1M - bammi