Re: Measuring coils with the FA-VA5 LCR mode
Hi Matt,
It is advisable to measure the coil at its operational frequency of 7 MHz. We never get pure coils. First and foremost there is a winding capacitance does affect the effective inductance. If
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Dieter VK3FFB
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#278
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Edited
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Re: Measuring coils with the FA-VA5 LCR mode
Hi Dieter,
When designing a coil for a 40m trap, would it be advisable to set the frequency to 7MHz?
Or would it be better near 1MHz for instance?
Thanks!
73'
Matt -WA0V
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Matt WA0V
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#277
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Re: Sweep generator - New feature
Hi Johnny,
thanks for your suggestion. Unfortunately the EEPROM in the FA-VA 5 is filled to 99 %. There is no space left for any new features. Also, there are no plans to issue a new firmware for the
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Michael DG5MK FA-VA5 creator
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#276
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FA-VA5 review
I own the FA-VA5 from 4 years, this is my review and description:
https://www.pianetaradio.it/blog/antenna-analyzer-fa-va5/
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Johnny IZ8EWD
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#275
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Sweep generator - New feature
I would suggest to Michael DG5MK a new feature, if is possible to add a sweep generator function, with these parameters:
- start/stop frequency
- number of points
- sweep time
I think it's not too
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Johnny IZ8EWD
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#274
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Re: Old Ham needs Help with TDR setup
Val,
Did you get any responses to your request for help? I don't see any posted in the forum.
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Robin Midgett
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#273
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New Chat: DG5MK e-mail contact
#chat-notice
A new chat has been created:
Hi Michael
My e-mail to your t-online address bounces back. Tried a few times. Please advise.
thanks
Dieter, VK3FFB
*By:* Dieter VK3FFB (group owner)
By
Group Notification <noreply@...>
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#272
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FA-VA5 user group member count soon reaching 200
Dear FA-VA5 users,
We may not be the most active group, but we meet the purpose of this group. Questions coming in from time to time are answered and discussed promptly.
It is now my pleasure to
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Dieter VK3FFB
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#270
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Re: SWR offset
If we consider the following:
The FA-VA5 measures impedance (Z) in a novel way devised by Michael, DG5MK. It then derives the VSWR via the reflection coefficient magnitude |rho|
VSWR = ( 1 + |rho| )
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Dieter VK3FFB
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#269
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Re: SWR offset
Thats my point. If you want to do a reliable vector smith chart analysis with the VA5, the self made calibration kit may be the bottleneck, even below 100MHz. But not for the SWR
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Peer DL8YF
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#268
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Re: SWR offset
No rush, Peer. Take your time. Jan already sent one pic.
SWR is a scalar number. (It is by definition the ratio of two voltage magnitudes |Vmax|/|Vmin| on a transmission line.)
73
Dieter, VK3FFB
By
Dieter VK3FFB
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#267
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Re: SWR offset
Hi Dieter,
Currently I'm on holiday. I will send the pictures as soon as I'm back home.
For the SOL topic up to 100Mhz,? youre right. A bit polemic :) On the other hand, in my setup Im not using
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Peer DL8YF
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#266
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Added album FA-VA5 BNC connector soldering
#photo-notice
Dieter VK3FFB (group owner) <dpelz@...> added the album FA-VA5 BNC connector soldering ( /g/fa-va5-users/album?id=281762 ) : This image was sent by Jan (SDR-KITS) to
By
Group Notification <noreply@...>
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#265
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Edited
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Re: SWR offset
Peer
Glad to hear you found the problem.
For the benefit of other FA-VA5 owners, it would be helpful if you could provide images of the BNC connector ground solder points.
Page 7 (... BNC socket)
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Dieter VK3FFB
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#264
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Re: SWR offset
I'll remember that in the future.
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Wes N7WS
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#263
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Re: SWR offset
For quick readers, the solution is down below!
Hi Dieter, Wes,
don't get me wrong. I highly appreciate tips and tricks for all kind of things. But, speculating and explaining basics isn't that
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Peer DL8YF
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#261
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Re: Calibration data
#fa-va5
In the meanwhile Jan send me the data via Email. Many thanks for your support, Jan! And, to keep it straight for readers, the Amphenol BNC CAL Kit sold via box73 and sdr-kits requires -41,66ps for
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Peer DL8YF
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#260
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Re: SWR offset
Hello Peer
I think Wes has already commented on the matter very well, so I am not going to repeat here.
The SWR detection inside amateur radio transceivers is not using an impedance measurement
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Dieter VK3FFB
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#259
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Edited
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Re: SWR offset
Hi Wes,
For that measurement shown in the pictues I simply swapped the connector between the Icom and the VA5. In general I would agree that the Icom SWR Bridge will be a bit behind the accuracy of
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Peer DL8YF
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#257
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Re: SWR offset
Hi Peer,
As I see it you have two different issues.
1) Disagreement between two different measuring devices
2) Some operational/calibration issues with the VA5.
Issue 1.? I assume that you are
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Wes N7WS
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#256
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