Re: SMA to banana binding post
On 7/20/22 10:12 AM, W0LEV wrote: SMA connectors are for good two reasons: 1) Small size and 2)
Frequency response.
SMA connectors are bad for one reasonable consideration: Limited service
lifetime for mates/demates. 500 mate/demate cycles is typical spec sheet number, but I'd say that there are plenty of SMAs that have seen a lot more cycles and are just fine, as long as they're not bent or damaged. There's a paper out there by some folks at Maury Microwave, where they mated/demated an SMA thousands of times with the intent of understanding the degradation in repeatability. The reason a spec sheet calls out a number like 50 or 500 cycles is because that's a "testing" number that is bigger than the customer is likely to use, but which is small enough that the price is reasonable. Typically it would derived from some MIL-STD and is basically a statement that the connector will meet the requirements after that many cycles. Another thing to watch out for is a loss or mismatch spec. Most connectors do NOT have anywhere near the loss in the data sheet, it's more driven by the lowest number that is practical to measure in a manufacturing environment. So an SMA (Amphenol M39012) at 1 GHz is 0.06 dB max loss - that's pretty close to the minimum measurable loss at 1GHz without going to a lot of trouble. Likewise, the mismatch (VSWR) is given as 1.05 to 1.20 plus some frequency dependent factor. It would be hard to measure a VSWR of 1.01 (46 dB RL), even if that is what the connector usually is. Banana jacks/plugs work fine at HF but not at or above 50 MHz. BNCs and
Type-N connectors are appropriate at and above 50 MHz. Top "careless" use
of BNCs is around 1 GHz. From there on upward in frequency, either SMA or
Type-N connectors should be used. Well, I'd say that banana jacks and similar single pin connectors are something that you need be aware of the non-ideal nature. Fortunately, with a NanoVNA, one can actually measure that non-ideal. If you must, SO-239 / PL-259 connectors are *only* for HF use. Their
impedance is NOT controlled as are the other referenced RF connectors.
True, the UHF connector isn't constant impedance, however, if you have a set of calibration standards in UHF, then that is managed in the calibration.
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Re: SMA to banana binding post
My understanding is that SMA connectors were originally designed for interconnections inside equipment which are usually installed and then not touched, so that the limited durability was not a factor; low cost was. It was only when they began to be used in test equipment that its durability shortcomings became apparent.
An improved design, intermateable with SMA, but with superior perfomance and durability and intended for test equipment, is the 3.5mm connector (and its derivatives, 2.9mm, 2.4mm, ...1.0mm, etc.) However it is also a precision connector so quite costly; but I am often able to convince my clients to install them on front panels of new test equipment we design.
Much of its improved performance is its use of air dielectric at the interface, which has more stable performance than the SMA's PTFE (Teflon?) interface with its variable air gap, and its beefier (thicker-walled) outer conductor construction.
I have purged my shack of UHF connectors; all cables are type N, BNC, SMA/3.5mm, or type F for RX-only. High-quality adapters or (preferably) replacement of equipment connectors when practical were used.
73, Don N2VGU
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Your filter looks fine, no funny stuff in the response. You might try expanding the scale of the S21 trace downwards to see how far down you can see the harmonic attenuation.
73, Don N2VGU
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Re: SMA to banana binding post
thanks
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On Wed, Jul 20, 2022 at 2:03 PM W0LEV <davearea51a@...> wrote: Try cutting double or single sided FR-4 board to the required shapes.
Also, useful thicknesses of small copper sheets are available at Ace
Hardware (and likely other outlets). Keep in mind that these days, copper
is not cheap!
Dave - W?LEV
On Wed, Jul 20, 2022 at 5:50 PM Fred Moore <n40cla@...> wrote:
Good afternoon Dave,
Do you know whether those copper blanks are available anywhere that can be
bought? I have tried making some with not much success.
Fred - N4CLA
On Wed, Jul 20, 2022 at 1:12 PM W0LEV <davearea51a@...> wrote:
SMA connectors are for good two reasons: 1) Small size and 2)
Frequency response.
SMA connectors are bad for one reasonable consideration: Limited
service
lifetime for mates/demates.
Banana jacks/plugs work fine at HF but not at or above 50 MHz. BNCs
and
Type-N connectors are appropriate at and above 50 MHz. Top "careless" use
of BNCs is around 1 GHz. From there on upward in frequency, either SMA or
Type-N connectors should be used.
If you must, SO-239 / PL-259 connectors are *only* for HF use. Their
impedance is NOT controlled as are the other referenced RF connectors.
Dave - W?LEV
On Wed, Jul 20, 2022 at 3:44 PM Observer <tvstreamdevice@...> wrote:
Anyone has or seen an sma male to an open banana binding post to
connect
to components ?
--
*Dave - W?LEV*
*Just Let Darwin Work*
--
Dave - W?LEV
--
*Dave - W?LEV*
*Just Let Darwin Work*
--
Dave - W?LEV
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Re: SMA to banana binding post
Try cutting double or single sided FR-4 board to the required shapes.
Also, useful thicknesses of small copper sheets are available at Ace
Hardware (and likely other outlets). Keep in mind that these days, copper
is not cheap!
Dave - W?LEV
toggle quoted message
Show quoted text
On Wed, Jul 20, 2022 at 5:50 PM Fred Moore <n40cla@...> wrote: Good afternoon Dave,
Do you know whether those copper blanks are available anywhere that can be
bought? I have tried making some with not much success.
Fred - N4CLA
On Wed, Jul 20, 2022 at 1:12 PM W0LEV <davearea51a@...> wrote:
SMA connectors are for good two reasons: 1) Small size and 2)
Frequency response.
SMA connectors are bad for one reasonable consideration: Limited service
lifetime for mates/demates.
Banana jacks/plugs work fine at HF but not at or above 50 MHz. BNCs and
Type-N connectors are appropriate at and above 50 MHz. Top "careless" use
of BNCs is around 1 GHz. From there on upward in frequency, either SMA or
Type-N connectors should be used.
If you must, SO-239 / PL-259 connectors are *only* for HF use. Their
impedance is NOT controlled as are the other referenced RF connectors.
Dave - W?LEV
On Wed, Jul 20, 2022 at 3:44 PM Observer <tvstreamdevice@...> wrote:
Anyone has or seen an sma male to an open banana binding post to
connect
to components ?
--
*Dave - W?LEV*
*Just Let Darwin Work*
--
Dave - W?LEV
-- *Dave - W?LEV* *Just Let Darwin Work*
--
Dave - W?LEV
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The NanoVNA DOES have a setting to display SWR. It just generates its own signal to measure it; it doesn't connect to a transmitter. The same with the RigExpert AA-600. It generates its own signal to display the SWR over the frequency range you choose. Last year I used the NanoVNA to measure the SWR of a small magnetic loop antenna wound on a ferrite bar and used in the 400 to 600 kHz range. And I've used it in SWR mode to tune loop Yagis for 902 and 1296 MHz. Zack W9SZ On Wed, Jul 20, 2022 at 12:50 PM W0LEV <davearea51a@...> wrote: Any amateur radio operator using a NANOVNA (or even the TinySA) should
absolutely know it's a low-power device and not fit for inline or
terminating installation!!!!!!! It ain't no Bird Wattmeter!!!!!!! If one
is not familiar with these sorts of test equipment, read the "welcome mat"
or "quick start" guide that is included in the box with all of them I've
bought (too many) well before even charging the unit(s)!!
Please.......please.........where did common sense go???? I know. Common
sense is not common and it is no longer taught.
Dave - W?LEV
On Wed, Jul 20, 2022 at 12:18 PM DougVL <K8RFTradio@...> wrote:
On Thu, Jul 14, 2022 at 07:56 PM, Ken wrote:
Be careful about suggesting using nanoVNA as an SWR Meter. Most SWR
Meters are
used between a transmitter and an antenna to show the SWR in the transmission
line at an operating frequency. The nanoVNA is connected to a transmission
line and antenna to show what the SWR will be when fed from a transmitter at
various frequencies. It would lead to disaster if someone connected a nanoVNA
between a transmitter and antenna.
That's another good reason or feature of the Nano's price! If you blow it
up (by transmitting into it), it probably won't break the bank. BUT if the
transmitter blows up too, well then you'll wish you looked (and learned)
before you jumped.
--
Doug, K8RFT
--
*Dave - W?LEV*
*Just Let Darwin Work*
--
Dave - W?LEV
<> Virus-free. www.avg.com <> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
|
Any amateur radio operator using a NANOVNA (or even the TinySA) should
absolutely know it's a low-power device and not fit for inline or
terminating installation!!!!!!! It ain't no Bird Wattmeter!!!!!!! If one
is not familiar with these sorts of test equipment, read the "welcome mat"
or "quick start" guide that is included in the box with all of them I've
bought (too many) well before even charging the unit(s)!!
Please.......please.........where did common sense go???? I know. Common
sense is not common and it is no longer taught.
Dave - W?LEV
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On Wed, Jul 20, 2022 at 12:18 PM DougVL <K8RFTradio@...> wrote: On Thu, Jul 14, 2022 at 07:56 PM, Ken wrote:
Be careful about suggesting using nanoVNA as an SWR Meter. Most SWR
Meters are
used between a transmitter and an antenna to show the SWR in the transmission
line at an operating frequency. The nanoVNA is connected to a transmission
line and antenna to show what the SWR will be when fed from a transmitter at
various frequencies. It would lead to disaster if someone connected a nanoVNA
between a transmitter and antenna.
That's another good reason or feature of the Nano's price! If you blow it
up (by transmitting into it), it probably won't break the bank. BUT if the
transmitter blows up too, well then you'll wish you looked (and learned)
before you jumped.
--
Doug, K8RFT
-- *Dave - W?LEV* *Just Let Darwin Work*
--
Dave - W?LEV
|
Re: SMA to banana binding post
Good afternoon Dave,
Do you know whether those copper blanks are available anywhere that can be
bought? I have tried making some with not much success.
Fred - N4CLA
toggle quoted message
Show quoted text
On Wed, Jul 20, 2022 at 1:12 PM W0LEV <davearea51a@...> wrote: SMA connectors are for good two reasons: 1) Small size and 2)
Frequency response.
SMA connectors are bad for one reasonable consideration: Limited service
lifetime for mates/demates.
Banana jacks/plugs work fine at HF but not at or above 50 MHz. BNCs and
Type-N connectors are appropriate at and above 50 MHz. Top "careless" use
of BNCs is around 1 GHz. From there on upward in frequency, either SMA or
Type-N connectors should be used.
If you must, SO-239 / PL-259 connectors are *only* for HF use. Their
impedance is NOT controlled as are the other referenced RF connectors.
Dave - W?LEV
On Wed, Jul 20, 2022 at 3:44 PM Observer <tvstreamdevice@...> wrote:
Anyone has or seen an sma male to an open banana binding post to connect
to components ?
--
*Dave - W?LEV*
*Just Let Darwin Work*
--
Dave - W?LEV
|
The NANOVNA can be used directly at 300-ohm resistance. Careful
calibrationn and placement of the cursor is required to ultimately read
values is required, but can be accomplished without introducing another
piece of uncertainty.
Dave - W?LEV
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On Wed, Jul 20, 2022 at 4:01 AM Observer <tvstreamdevice@...> wrote: Anyone has used the nano with an antenna bridge ( or noise bridge ?) to
measure antenna impedances other than 50 ohms, like 300 ohms and up ?
-- *Dave - W?LEV* *Just Let Darwin Work*
--
Dave - W?LEV
|
Re: SMA to banana binding post
SMA connectors are for good two reasons: 1) Small size and 2)
Frequency response.
SMA connectors are bad for one reasonable consideration: Limited service
lifetime for mates/demates.
Banana jacks/plugs work fine at HF but not at or above 50 MHz. BNCs and
Type-N connectors are appropriate at and above 50 MHz. Top "careless" use
of BNCs is around 1 GHz. From there on upward in frequency, either SMA or
Type-N connectors should be used.
If you must, SO-239 / PL-259 connectors are *only* for HF use. Their
impedance is NOT controlled as are the other referenced RF connectors.
Dave - W?LEV
toggle quoted message
Show quoted text
On Wed, Jul 20, 2022 at 3:44 PM Observer <tvstreamdevice@...> wrote: Anyone has or seen an sma male to an open banana binding post to connect
to components ?
-- *Dave - W?LEV* *Just Let Darwin Work*
--
Dave - W?LEV
|
New users of the NanoVNA have many questions about their new piece of test equipment. They will find a lot of useful information and User Guides in the Files section of this group. /g/nanovna-users/filesAnswers to common questions and how to information in this group's Wiki /g/nanovna-users/wikiOver the years most questions have been answered more than once by other members. Just use the search feature of groups.io to find previous relevant posts in this group. Roger
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Re: SMA to banana binding post
On 7/20/22 8:44 AM, Observer wrote: Anyone has or seen an sma male to an open banana binding post to connect to components ?
Typically, I use a BNC-dual banana jack and a SMA/BNC adapter. I don't know that anyone sells a SMA-Banana I've built them over the years. Usually, by cutting a SMA-SMA cable, splitting the coax and using a dual jack or plug - or by using individual jacks or plugs on the two conductors. To get a decent calibration (if needed) you want to anchor the wires to the binding posts, so that they don't move.
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On 7/20/22 7:08 AM, Observer wrote: I have found the most, mouthful fed examples on how to use a vna.
But, can the miniVNA measuring techniques be directly applied to nano ?
In general yes. The miniVNA uses a different receiver design, and different ways of sampling the signals, but the basic concept is the same - look at reflected signal vs incident signal. Calibration done a similar way. I looked through the first part of that writeup and it all looks like straightforward stuff.
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On Wed, Jul 20, 2022 at 07:08 AM, Observer wrote:
I have found the most, mouthful fed examples on how to use a vna.
But, can the miniVNA measuring techniques be directly applied to nano ?
Yes
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Re: SMA to banana binding post
Try reading this groups's Wiki to learn more about testing jigs to measure components.
Roger
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SMA to banana binding post
Anyone has or seen an sma male to an open banana binding post to connect to components ?
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yes,
now go measure with your nano if you have one.
What is your name? (second time I ask)
Op 20-7-2022 om 16:08 schreef Observer:
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I have found the most, mouthful fed examples on how to use a vna.
But, can the miniVNA measuring techniques be directly applied to nano ?
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I have found the most, mouthful fed examples on how to use a vna.
But, can the miniVNA measuring techniques be directly applied to nano ?
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Donald S Brant Jr
Roger Need
Arie Kleingeld PA3A