Dear friends,
I have found a source for 7/16 DIN Tees, a species that I formerly thought
was extinct in the wild.
https://www.segemart.com/7-16-din has them at reasonable prices. I ordered
two and they were delivered promptly. With an Agilent N9923A, I measured >
35 dB return loss (one port open) and through-loss of 0.004 dB.
73,
W9IP
I have for sale
3 pices 1296 MHz LNA from VHF Design, 2 with sma con. and one with N con. 1100:- SEK /etch
1 pice of G4DDK LNA 1100:- SEK
Also my own LNA and more 1296 MHz equipmemt, see my home page, sm5dgx.se
Price is + shipping
/anders sm5dgx
Hello, Moon-net.
In the latest version of the WSJT-X the information in the
"Last TX" field (the lowest line of the main program window
on the left,) has disappeared. By default, it is set to Russian,
could this be the reason?
--
Best regards
Arkady, UT9UR mailto:ut9ur@ukr.net
Hi Alberto,
Peter PA2V is quite right there can be a lot of variation in measurements
made with a Bird 43 Thruline power meter and a Bird dummy load.
Some of this is due to variations in the Bird elements, typically 10% but
also the exact configuration of the test set-up.
Not all cables are exactly 50 ohms impedance at 144MHz (worse on
432/1296MHz) and neither are many dummy loads.
Besides the actual load impedance and the phase of any reflections
(including harmonics!) there is also an issue that I suspect that many high
power amateur SSPAs are sensitive to some common mode feedback when the load
is not perfect. I have found that with my Italab 144MHz amplifier that, for
a fixed driver output, I can measure around 25% difference in amplifier
output power depending upon the exact cables and lengths. I reduced this to
around 10% by placing a dual circulator/isolator on the input. Even with the
same load I could still measure noticeable differences with different
sorts/lengths of well matched cable to the load. I tested LDF4-50, FSJ4-50B,
Cellflex and Amphenol ½ inch superflex at various lengths and all gave
different results.
If I was a manufacturer I would of course select the load and cable
combination that gave the best looking results!
John G4SWX
Date: Fri, 20 Jan 2023 13:52:33 +0100
From: "PA2V" <pa2v(a)advipe.nl <mailto:pa2v@advipe.nl> >
To: <moon-net(a)mailman.pe1itr.com <mailto:moon-net@mailman.pe1itr.com> >,
"'IZ2EWV Italian amateur radio
station'" <iz2ewv(a)gmail.com <mailto:iz2ewv@gmail.com> >
Subject: Re: [Moon-Net] calibration of RF power meter
Message-ID: <003001d92cce$10a8e6d0$31fab470$(a)advipe.nl
<mailto:003001d92cce$10a8e6d0$31fab470$@advipe.nl> >
Content-Type: text/plain; charset="utf-8"
Hi Alberto,
I have done quite some measurements with a Bird 43.
As far as I know Bird always claimed an accuracy within 1 dB, which is of
course 25%.
So your readings are within specifications. And yes, every other
termination(your dummy) will introduce different readings.
A Bird 43 is just a transmission line of around 50 Ohm, cables, termination,
etc. will have their effects of the field measured with your slug.
Exact power measurements are difficult and not easy. There are other methods
using a coupler, but this is an other field with errors and difficulties.
I would be suspicious at the slug, they vary quite a lot?.. I have seen 1000
Watt types reading between 800 and needle in the right corner.
Good luck and 73,
Peter PA2V
Date: Fri, 20 Jan 2023 11:56:21 +0100
From: IZ2EWV Italian amateur radio station <iz2ewv(a)gmail.com
<mailto:iz2ewv@gmail.com> >
To: Moon-net <moon-net(a)mailman.pe1itr.com
<mailto:moon-net@mailman.pe1itr.com> >
Subject: [Moon-Net] calibration of RF power meter
Message-ID: <7A16A35B-33E5-4B92-AC9C-07066B22E18C(a)gmail.com
<mailto:7A16A35B-33E5-4B92-AC9C-07066B22E18C@gmail.com> >
Content-Type: text/plain; charset="utf-8"
Hello dear friends!
Recently I dealt with a 500 W SSPA for 2 m band, which I sent to the factory
for repair. After the repair, the factory sent me a photo of the circuit and
the test, showing a Bird model 43 power meter with a slug type 500C, which
measured more than full scale (should be 520-530 W).
Arrived at my QTH and tested again (CW) with my instruments (Bird 43 with
slug 500C - both of them second hand), the maximum reading that I obtained -
terminated to a Bird 500 W dummy load - was 400 W. I also tested again by
changing dummy load (I have a 1 kW Bird too), the power meter (a second Bird
43) and the cables, but not the slug because I have only that one: the
reading changed to 420 W and I arrive at the conclusion that - except for
the slug - all the other instrumentation is good (the model 43 declares 5%
accuracy of full scale, which is 25 W for a 500 W slug).
I have no doubts about the measure carried on by the manufacturer of the
SSPA, which I suppose that uses periodically calibrated instrumentation:
therefore I guess that my 500C slug is not so good.
My question is: how is it possible to check the accuracy of a RF power meter
(and eventually adjust it to the best, if possible) for a OM like me, who
works with reconditioned instrumentation and, obviously, will not bring it
to a recognised laboratory for calibration? Is there available a procedure,
good for whatever frequency the power meter covers?
Tnx es 73 de
Alberto Calderara
Via Santa Marta, 26
20871 Vimercate (MB) - Italy
IZ2EWV amateur radio station
ITU 28 ? CQ 15 ? WWL JN45qo
SKCC #18930
iz2ewv(a)alice.it <mailto:iz2ewv@alice.it> <mailto:iz2ewv@alice.it> /
iz2ewv(a)gmail.com <mailto:iz2ewv@gmail.com> <mailto:iz2ewv@gmail.com>
http://www.iz2ewv.altervista.org <http://www.iz2ewv.altervista.it/>
http://www.arimonza.it
Thanks Lionel and all for the answers!
Regarding antenna boom, I read in the User Manual for EZNEC the following:
"Yagi Antennas A conductive boom, whether electrically connected to the
elements or not, can modify Yagi antenna operation in some cases. However,
if an antenna is perfectly symmetrical and the boom is exactly along the
center line of the elements, EZNEC will not show any effect from it
regardless of its diameter."
I am not sure how to understand this. Has anyone done a modeling with EZNEC
that can show how an antenna boom who has a distance to the element so no
need of boom correction is needed will efekt the Yagi performance.
73 de Stig SM4GGC
Den ons 18 jan. 2023 kl 21:32 skrev Lionel H. Edwards <ve7bqh(a)shaw.ca>:
> HI Stig:
>
> Yes but you have not included the whole antenna. By that I mean you must
> include the booms of the antenna as that is the real antenna. You will see
> quite different results when you include the metal booms.
>
> Lionel, VE7BQH
>
>
>
>
>
>
>
> At 03:57 AM 2023-01-18, you wrote:
>
> I have done some antenna modelling with EZNEC Pro/2 v7.0 and tried to
> investigate how stacking antennas on different bands works and wonder if I
> can trust the result?
>
> First case is a 2m antenna close to 70 cm in vertical stacking.
> Second case is 6m antenna close to a 2m antenna
> Picture: https://sm4ggc.se/2m_70cm_6m-layoute.jpg
> Se table below
> Ref ant. 2m YU7EF EF0213M Gain 16,1 dBiÂ
> Ref. ant 70cm YU7EF EF7027 Gain 19,6 dBiÂ
> 2m 13 el and 70cm 27 el Yagi
> Distance between antennas vertically Gain 70 dBi Loss 70cm Gain 2m dBi
> Loss 2m
> 17,5 cm* 17,12 -2,5 16,1 0
> 35 cm 18,24 -1,4 16,1 0
> 70 cm 19,15 -0,5 16,1 0
> 1400 cm 19,6 0 16,1 0
> Ref ant. 2m YU7EF EF0213M Gain 16,1 dBiÂ
> Ref. ant. 6m YU7EF EF0605A Gain 10,8 dBiÂ
> 2m 13 el and 6m 5 el Yagi
> Distance between antennas vertically Gain 2m dBi Loss 2m Gain 6m dBi Loss
> 6m
> 50 cm 15,4 -0,6 10,8 0
> 100 cm 15,7 -0,4 10,8 0
> 200 cm 16 -0,1 10,8 0
>
> As you can se are is it only possible to notice degradation on the antenna
> with highest frequency is that the truth or is it some malfunction in theÂ
> modelling software?
>
> I did also tested this setup with 4 old 21 el Tona 432 on the same
> vertical bom as 2 13 el YU7EF 2m and on the other side also 2 13 el YU7EF
> with a 5 el YU7EFÂ below on same vertical boom
> Se picture with result: https://sm4ggc.se/Ant_SM4GGC_mast.jpg
> On the picture:Â
> To the Right on top 6m antenna
> To the Left bottom 4x13 el 2m in square stacking
> To the Right bottom 4X21 el 70cm Vertical stacking
> Result seems good with only marginell effect on gain (-0,3 dB on 70cm) and
> antenna pattern! But is it to trust?
>
> 73 Stig SM4GGCÂ Â Â
> Â
> _______________________________________________
> Moon-Net posting and subscription instructions are at
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>
>
>
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> Virus-free.www.avast.com
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>
>
Hello dear friends!
Recently I dealt with a 500 W SSPA for 2 m band, which I sent to the factory for repair. After the repair, the factory sent me a photo of the circuit and the test, showing a Bird model 43 power meter with a slug type 500C, which measured more than full scale (should be 520-530 W).
Arrived at my QTH and tested again (CW) with my instruments (Bird 43 with slug 500C - both of them second hand), the maximum reading that I obtained - terminated to a Bird 500 W dummy load - was 400 W. I also tested again by changing dummy load (I have a 1 kW Bird too), the power meter (a second Bird 43) and the cables, but not the slug because I have only that one: the reading changed to 420 W and I arrive at the conclusion that - except for the slug - all the other instrumentation is good (the model 43 declares 5% accuracy of full scale, which is 25 W for a 500 W slug).
I have no doubts about the measure carried on by the manufacturer of the SSPA, which I suppose that uses periodically calibrated instrumentation: therefore I guess that my 500C slug is not so good.
My question is: how is it possible to check the accuracy of a RF power meter (and eventually adjust it to the best, if possible) for a OM like me, who works with reconditioned instrumentation and, obviously, will not bring it to a recognised laboratory for calibration? Is there available a procedure, good for whatever frequency the power meter covers?
Tnx es 73 de
Alberto Calderara
Via Santa Marta, 26
20871 Vimercate (MB) - Italy
IZ2EWV amateur radio station
ITU 28 – CQ 15 – WWL JN45qo
SKCC #18930
iz2ewv(a)alice.it <mailto:iz2ewv@alice.it> / iz2ewv(a)gmail.com <mailto:iz2ewv@gmail.com>
http://www.iz2ewv.altervista.org <http://www.iz2ewv.altervista.it/>
http://www.arimonza.it
Bird 43 is very old device, together with slugs not precise RF meter, specially in the first 1/2 of scale. For precise measurement I'm using RF sampler slug, maximum 500W of power, 50dB attenuation and for frequency up to 1GHz, connected to spectrum analyzer with additional 20dB attenuator.In your presented data missing few very importants informations: PA power supply voltage and power consumption (presume 50V system?) to compare with factory settings.73, Goran yt7pwrPoslato sa mog uređaja Galaxy
