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Where can I get the attenuators for the TinySa?
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AliExpress carry a big range of attenuators. for a cheap and
cheerful 'safty' attenuator there is a board with 30, 20 and 10dB
and a 0dB on the same PCB for about $5. Search AliExpress for ...
diymore DC
-4.0Ghz RF Fixed Attenuator Module Board
On 12/06/2024 22:47, Dom via groups.io
wrote:
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Where can I get the attenuators for the TinySa?
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Dave's Hobby Shop (w5swl.com) aften has a good mix of surplus SMA attenuators. Dave is a good guy and I've always been satisfied. I've also found good deals on new and gently used Mini-Circuits attenuators on eBay when Dave doesn't have what I need. 73 -Jim NU0C On Wed, 12 Jun 2024 14:47:48 -0700 "Dom via groups.io" <domesi2005@...> wrote: Where can I get the attenuators for the TinySa?
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AliExpress... maybe you get what you pay for.?
I got my attenuators from Dave's at W5SWL.COM - no problems, easy transaction, prompt shipment. Inventory varies, and it takes a little hunting to find the right parts, but they're there. Email asking about a couple of items was answered quickly.?
73
Rick
KC3DOO
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I've purchased a lot of them on eBay. Enter "sma attenuator" in the search window. Since I do a lot of microwave construction and measurement, I have a whole set of attenuators that are good to 18 GHz.
Zack W9SZ
Where can I get the attenuators for the TinySa?
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Stating the obvious for some folks, but...
When putting an attenuator on a TinySA, the /first/ attenuator in a chain of attenuators (including a chain of one) should be rated to handle the full power being sent to the TinySA, at the far end of the chain.??
73
Rick
KC3DOO
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When putting an attenuator on a TinySA, the /first/ attenuator in a chain of attenuators (including a chain of one) should be rated to handle the full power being sent to the TinySA, at the far end of the chain.??73RickKC3DO
?
As Rick says - also be aware most non-professional attenuators rated over 0.5W only have?one end that can handle the full printed rated power? ?
On some this is indicated by a stuck on arrow (with self-detach-over-time-function) while for others there is no clue apart from an unwritten convention that the 'male' plug end is the source /high power end.? ?(Except not always ???).?
On 2W and 5W? SMA attenuators the 'Male plug =high power end' rule generally applies and often if you get your best magnifying glass out you see?SU? (Which I read somewhere is Source/Upstream)? engraved on the outer 'Nut part' of the SMA male.? ?
Generally this will only bother you on the first attenuator as most are bi-directional once the level is less than 0.5W? (+27dBm) but its not a bad idea to consider it every time so it becomes automatic for when you are in a rush . .? ? ? (Also always check the pins on random SMA connectors before mating them is a pretty good rule to run with)
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apart from an unwritten convention that the 'male' plug end is the source /high power end.?
Aha, but is that the male centre pin end, or the male thread end? This gender description always gets me! Peter
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On 13/06/2024 16:23, Prawlin via
groups.io wrote:
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apart
from an unwritten convention that the 'male' plug end is the
source /high power end.?
Aha, but is that the male centre pin end, or the male thread end?
This gender description always gets me!
Peter
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On Thu, Jun 13, 2024 at 03:23 PM, Prawlin wrote:
Aha, but is that the male centre pin end, or the male thread end? This gender description always gets me!
Better stick with hermaphroditic connectors, such as the General Radio Type 874, but they are a bit bulky. Otherwise, this may (genuinely) help Regards, Martin
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Oh my goodness
?
Perhaps this will help - my description of the high power 'SMA Male end' below complies with this convention? (pic attached)?
(Which includes RP options to illustrate that your native-logic is no help at all in this area)
?
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>> The "centermost" conductor gives
the gender...except in reversed gender connectors!
>> John
>> at radio station VE7AOV
++++++++
On 2024-06-13 08:23, Prawlin via
groups.io wrote:
apart
from an unwritten convention that the 'male' plug end is the
source /high power end.?
Aha, but is that the male centre pin end, or the male thread end?
This gender description always gets me!
Peter
_._,_._,_
--
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It should be rated to handle the *dissipation* in that unit. So if you put 10 W total into a 3 dB attenuator then it needs to be rated for 5 W dissipation.
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I suggest the opposite...
If the radios output is 100w.? Then absolute minimum wattage is 100 Watts.? That's ok if you don't transmit longer than few seconds.? Otherwise I'd choose, at least, twice the expected output (200w). 3x is the better, if the transmission time is many minutes.
Another thing.? The rated power of 100w, 3db load, bought on ebay or Amazon, is likely not 100w - But 100w for one or two seconds, before it blows.
Best regards, Bruce Hawkins - AC6DN.? Sent from my Android phone.? And from: ac6dn@...
On Jun 14, 2024 3:39 AM, Wiggle Pig <wigglepig@...> wrote: It should be rated to handle the *dissipation* in that unit. So if you put 10 W total into a 3 dB attenuator then it needs to be rated for 5 W dissipation.
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That too depends. I've purchased INMET and Mini-Circuits product on eBay. All seem to be as advertised. On Fri, 14 Jun 2024 13:05:06 -0500 "Bruce Hawkins via groups.io" <ac6dn@...> wrote: Another thing.? The rated power of 100w, 3db load, bought on ebay or Amazon, is likely not 100w - But 100w for one or two seconds, before it blows. -- 73 -Jim NU0C
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This has been pointed out previously by another ham.? If one starts with 100-watts from the transmitter in CW, RTTY, or the digital modes, what is dissipated in a 3 dB attenuator?? NOT the full 100-watts.? The 3-dB attenuator "eats" 50-watts and PASSES along 50-watts at its output.? Therefore, it dissipates 50-watts.? If properly spec'ed, that should be for "key down" conditions for a very long time.? Another 3 dB attenuator would "eat" 25-watts and pass along 25-watts.? It should dissipate 25-watts for a very long time.?
Take the statement from the previous post:? (QUOTE):?
If the radios output is 100w.? Then absolute minimum wattage is 100 Watts.
This statement is just not true.? If you needed to dissipate ALL of your 100-watt power, that would require a dummy load, and NOT an attenuator.? And, then, yes, it would need to be a 100-watt DUMMY LOAD with NOTHING out the "other end" as there is no "other end" with a dummy load.
Dave - W?LEV
I suggest the opposite...
If the radios output is 100w.? Then absolute minimum wattage is 100 Watts.? That's ok if you don't transmit longer than few seconds.? Otherwise I'd choose, at least, twice the expected output (200w). 3x is the better, if the transmission time is many minutes.
Another thing.? The rated power of 100w, 3db load, bought on ebay or Amazon, is likely not 100w - But 100w for one or two seconds, before it blows.
Best regards, Bruce Hawkins - AC6DN.? Sent from my Android phone.? And from: ac6dn@...
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I actually bought a set of 1,2,3,6,10,20,30,40dB attenuators, advertised as 2W? DC-8G from aliexpress (So cheap that I thought that if they are junk then I will just file 13 them). I tested them on my NanoVNA-H4 and was surprised to find that all of them tested to be within 0.02 and 0.1dB below the stated value. They also measured to have a VSWR below 1.2:1 all the way up past 2GHz, I didn't bother testing higher in frequency as I don't need anything higher than 1.5GHz at the very highest. I won't be even thinking about putting more than 1-100mW through them. I will be using quality high power attenuators before them and only using them to fine tune attenuation levels that I need. Or using something like a 60dB RF tap just to sniff off a very small signal where those attenuators will become useful.
I fully expect to have many people argue with my logic for buying them and how I intend to use them, but in my opinion, if you keep your wits about you then there shouldn't be a problem as long as you test them properly first and don't expect them to handle anything like the power they say. Like I said, I'm only ever going to put 5% MAX of the stated power through them, which I cannot see as a problem.
The TinySA and NanoVNA are (with no dissrespect) budget test equipment. Most people using them will start with budget accessories. If they need to upgrade to better equipmet at higher costs then they will do as their needs require.
Just my ?0.02p
Paul
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Hi Paul,
Just a little tongue in cheek, but I happen to
have a couple of Agilent N9342N (aka: HP dc to daylight spec
anal) that track in the ballpark of $12k and weigh a 'ton'.
Certainly can't put them in your shirt pocket but Erick's little
'tweaky-treasure' gets my vote every time. Just sayin'? :0)
Mike C. Sand Mtn GA
On 6/14/2024 6:37 PM, m0cnl wrote:
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<snip>
The TinySA and NanoVNA are (with no dissrespect) budget test
equipment. Most people using them will start with budget
accessories. If they need to upgrade to better equipmet at higher
costs then they will do as their needs require.
Just my ?0.02p
Paul
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On Sat, Jun 15, 2024 at 02:10 AM, Mike C. wrote:
Hi Paul,
Just a little tongue in cheek, but I happen to have a couple of Agilent N9342N (aka: HP dc to daylight spec anal) that track in the ballpark of $12k and weigh a 'ton'. Certainly can't put them in your shirt pocket but Erick's little 'tweaky-treasure' gets my vote every time. Just sayin'? :0)
Mike C. Sand Mtn GA
Hi Mike, Lucky you, but in essense it seems that you are saying the same as me. The TinySA and NanoVNA are tremendous pieces of equipment (even more so for the price point). No way would they compare on how exactly they measure up to that piece of equipment, but for the price there is absolutely zero comparrison. For 90% of what I want, they are more than adequate for the basic/average/above average user eg 99% of Hams. An SA or VNA in this price point is unheard of and has to be absolutely applauded. You cannot buy DEAD equipment on Ebay for less than 5x the price. Paul
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The small SMA attenuators are symmetrical. SU stand for Semi United the company that makes them. 
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mike
Jim Shorney
Richard B. Emerson
Bruce Akhurst
Mike C.