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 Sark 100 
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Post Sark 100
Not the best analyser in world but certainly a budget one. :this:
Been a bit disappointed with mine BUT there is light end of the tunnel. :bye:

When checked out there Web site they do say it needs regulating configuration. ;)

So found some little baccy tins and make some mini dummy loads, 3 in fact 50 150 and 274 ohm. No need for oil for large Resistors film 1/4w plenty enough as you NOT going to put TX power through them just the signal gen signal.
:beg:
Very easy to do and finally finished the last one today. :clapping:

Put the Sark on its mains line via PSU and found the readings after configuration were quite good.
Found me 40m loop hoz HB is res about 6.984mhz at its low point at 1.4 and the swr bridge is showing 1.2 same freq. So am happy with that. And its showing no reactant or cap as you would expect from a full wave loop for 40m. But looks like going have to trim it down to bring the dip up the band a bit from 6.984 to more 7150 and hopefully me Imp will increase some what from 30-Ohm. Plus take the feeder part the Q stub further away from house to back of garden and run extra bit of RG215. And but the small amount of RF from the system. :shock:


PLUS make sure battery's are at least 800 mah recharges as when they run down reads off funny also hence preserve using the mains PSU/ Oh wise the Sark 100 works well once configured and reg do it. :D

Next job is build a tri 0hm unit with only one PLL female chassis and switch able mini dummy loads. Change having to change single units every time you want to reconfigure the unit :hello:


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Thu Sep 12, 2019 12:50 pm
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 Sark 100 
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Post Re: Sark 100
I've not seen a sark 100, but are you using a lead to connect it to the tins with resistors in?
If so any calibration is compromised unless the lead is always used in measurements

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Thu Sep 12, 2019 10:59 pm
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 Sark 100 
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Post Re: Sark 100
Good point and thanks for that use leads used is same on antennas :-)

I did a multi version in one tin with switch but its Rx is effecting readings some what.

So onto next stage of making calibration tools for me Sark 100 on where a Rx and uH iwll be kept to a min and no leads required. SMD carbon resistors into PLL plugs keeping the tails off the SMD to a MIN.

FB can be a pain and get loads criticisms but no one to say ok that,s good but this is better and try this with these parts and given some instructions. Need more people on there to take hold and guide you forwards not just blab on no that,s wrong with no guidance forwards. One chap has given me that guidance with out the full on simple science that baffles the pants of me.

Moving forwards again to better calibration tools for me sark 100


Sat Sep 21, 2019 7:34 am
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 Sark 100 
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Post Re: Sark 100
I'm not sure what values you need to make the calibration
standard 3 part kits use terminated (50 ohm) open and short.
Like this kit here; https://www.ebay.co.uk/itm/132920166071

You will have to post some pictures of the sark in action, because from your description you know how to use it, rather than the often 'find the lowest SWR / never mind the LC value or actual resonance' approach.

Do you need to keep calibrating it?
I had an MFJ one some time ago, you only calibrated it once, or recalibrated if you wanted the test point at the end of a cable.

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Sat Sep 21, 2019 6:45 pm
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 Sark 100 
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Post Re: Sark 100
Just a "never used an antenna analyser" persons question, having used the numerous old school methods for years, from simple SWR meters to Grid dips, following suitable prior mathematical calculations of course, and I am sure everyone is aufait with them?
If at the end of the day, the "all singing and dancing" analyser tells you everything should be "honky dory" and the antenna still behaves "on air" like a piece of damp string, do you do as I have always done, with my most basic of test equipment and calculations, simply try again with something else, or do you spend hours wondering why the marvelous "measured" results, don't quite equate to marvelous "on air" results?
Just saying, as a dummy load gives pretty good measured meter results, and that ain't going to get you very far! ;)

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Sat Sep 21, 2019 10:11 pm
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 Sark 100 
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Post Re: Sark 100
My wisdom is;
If you put a dipole up, it will work

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Sat Sep 21, 2019 10:19 pm
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 Sark 100 
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Post Re: Sark 100
GW6RRL wrote:
My wisdom is;
If you put a dipole up, it will work

And of course a three element basic Yagi is just a variant of a dipole with reflector and director! ( and at a push a slightly different feed point arrangement) :)
I just don't buy into this fancy screen antenna analyser hype, sorry for being a old fossil! :)
To fully appreciate what might be wonderfully graphically displayed in front of you, surely you must already have more than an inkling of what it's display actually means in the real World, and if you have never dabbled "old school" nuts and bolts, how does that work?

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Sat Sep 21, 2019 10:26 pm
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 Sark 100 
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Post Re: Sark 100
They do help with things like - is it resonant, rather than just trimming for low SWR and hoping the feed point is about matched, and when you start throwing complex shapes in a small garden, adding inductors etc.
I've been there, but I'm pretty lucky now, I can just measure out two 1/4 waves and stick them in the air, whatever band.

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Sat Sep 21, 2019 11:50 pm
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 Sark 100 
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Post Re: Sark 100
Tt instructs you to start with the 50ohm load cals then asks for the 150 load etc etc
Now going to do SMD versions of dummy load simple,s inside of PLL plugs. keeps the reaceance down etc.

But been interesting getting to this stage and still like to use old meter wise to check if its about right and the sark informs me of other measurements the SWR meter does not


Sun Sep 22, 2019 8:45 am
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 Sark 100 
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Post Re: Sark 100
G0BHD wrote:
GW6RRL wrote:
My wisdom is;
If you put a dipole up, it will work

And of course a three element basic Yagi is just a variant of a dipole with reflector and director! ( and at a push a slightly different feed point arrangement) :)
I just don't buy into this fancy screen antenna analyser hype, sorry for being a old fossil! :)
To fully appreciate what might be wonderfully graphically displayed in front of you, surely you must already have more than an inkling of what it's display actually means in the real World, and if you have never dabbled "old school" nuts and bolts, how does that work?


If you did a fair amount of antenna experimenting, and you tried a graphical analyser, you would appreciate what you saw.

If it is just a dipole, you can see instantly where the dip is.
Of course you could do the same with an SWR meter.

If you were tuning a cobweb, you could see instantly where all the dips are, and how adjusting one will affect the others.
Again you could do the same with an SWR meter.

If you are adjusting a 2m gamma match (never use them, but just an example) you can see the effect as you adjust it.
You could adjust it using an SWR meter.


If I want to travel from Coventry to Devon, I would still get there if I used a donkey cart :)

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Sun Sep 22, 2019 8:56 am
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 Sark 100 
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Post Re: Sark 100
https://sites.google.com/site/ea4frb/antenna-analyzers/sark100/Archive#TOC-SOFTWARE

If you fancy making your own SARK-100 ?
I have 4 pcbs available :hello:

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Wed Sep 25, 2019 12:45 am
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