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Post by coljambro on Jul 17, 2011 9:47:17 GMT -5
G3isb(new member, coljambro) recent purchase of AIM4170C. Find no mention of 'Syc' facility in op. instructions. Can someone please elucidate?
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Post by Gi4CZW on Jul 18, 2011 15:40:10 GMT -5
If you hunt down these Topics to Mar 14 2010 and open "4170C Sync Port Question". Cliff.
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Post by pacopete on Aug 25, 2011 15:57:34 GMT -5
Hi Bob,
I have been using the AIM4170 for some years now but I have reason to suspect my custom calibration procedure may be wrong.
I use a length of RG super8 as the connector to test and experimental antennas for HF. I have calibrated this cable from 3 to 30MHz with delta frequency of 0.1MHz. I have used this cable when measuring and recording the SWR/Z characteristics of a magnetic loop in the HF bands 14 to 28MHz.
On rereading the calibration instructions I note that a small delta f should be used but if I go to a delta f of 0.01MHz this would result in 3000 cal points. The instructions indicate a maximum of a 1000.
My question: is a delta f of 0.1 adequate if there are no filters involved.
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Post by Bob on Aug 25, 2011 16:06:16 GMT -5
Hi Pacopete,
You may need a smaller frequency step for a narrow band antenna.
The new version of the program allows up to 30,000 cal and data points.
--73/Bob
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Post by pacopete on Aug 25, 2011 16:36:38 GMT -5
Hi Bob,
Thanks for the info. I am still running on AIM685 so a S/W upgrade appears to be in order, which will sort the calibration problem (if indeed there was a probem).
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g3nrw
Junior Member
Posts: 54
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Post by g3nrw on Aug 26, 2011 5:24:46 GMT -5
Bob
This reminds me of a suggestion that I meant to make some time ago. When custom calibrating a coax cable for the HF bands, I have up to now done a separate custom calibration for each of the bands -- this is OK, but it means typically 13 separate calibration runs (one for each band, 4 for 10m).
Now that the data storage limit is increased to 30,000 items, this would mean I could calibrate the cable from 1-31MHz in one go, with a frequency step of 1 kHz. However, when viewing a subsequent custom scan, I would only be able to see the whole 30MHz range. Is there any possibility of adding a zoom feature that lets you zoom into any sub-range of interest?
--
73
Ian, G3NRW
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Post by Bob on Aug 26, 2011 10:13:02 GMT -5
Hi Ian,
There isn't a zoom feature per se but you can select a sub-range of the custom cal range and rescan to get better resolution in a particular band. You can have one large cal file to cover all the bands. Then you don't have to reload cal files when changing bands.
When scanning a multiband antenna, you can use the Band Skip mode to skip over the unwanted frequencies for faster scanning. The skipping is determined by the band definitions in the config file, which can be customized for particular applications.
--73/Bob
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zl4kx
New Member
Posts: 1
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Post by zl4kx on Sept 1, 2011 9:34:15 GMT -5
Hi Bob
I am laying claim to the most southerly use of an AIM uhf so far, here in my work in Antarctica (64South). I am VERY pleased with its operation. Measurements which used to take hours are done in minutes now.
My understanding of theory has improved greatly in the short time I have been using the analyzer. Thanks for such a great device!
73 Bede
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Post by Bob on Sept 1, 2011 14:15:40 GMT -5
Hi Bede, Thanks very much for the report. I'm please to hear it works well at low temps.  vy 73/Bob |
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Post by mbrioso on Oct 3, 2011 23:37:06 GMT -5
Hello everyone On today I received my AIM uhf and a few hours of having, it helped me to solve a problem. I was in the process of tuning an antenna in the FM commercial band and everything was perfect with the antenna at low height, but when this was raised my other analyzer gave erratic readings from the influence of two local radio stations (this gave me a tremendous confusion, because I thought it was an antenna problem). Once I familiarize a litle bit with the AIM uhf, I determine that the antenna was properly and have a new approach to the problem, it was a new amp that was testing (works great with dummy load!), and since it see a reactive load even with a few watts out it begins to protect itself  ) I put the other amp and everything perfect! ...... a wonderful start. |
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g4zow
New Member
Posts: 4
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Post by g4zow on Oct 5, 2011 2:31:12 GMT -5
Hi Bob,
What are the chances of going to USB in place of the serial connector on the AIM 120 or 4170 in the future?
Also, I wonder if going to a dual-port analyzer would add greatly to the cost?
I am considering a 120 for field use and can offset some of the investment by disposing of my existing heavyweight equipment!
Thanks.
David G4ZOW
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Post by Bob on Oct 5, 2011 9:39:38 GMT -5
Hi David,
We will probably stick with the present interface on the AIM4170 and PowerAIM120. The AIMuhf does have a usb interface.
The VNA2180 is a two port instrument. It can handle a larger interfering signal than the AIM4170. It goes up to about 2V on the input (the PowerAIM goes up to 25V). The VNA2180 is like the AIM4170 on Port A, so it's good for measuring antennas as well as filters. The VNA2180 can also be used with an external multiplexer which helps when tuning antenna arrays.
--73/Bob
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Post by mbrioso on Oct 8, 2011 0:19:58 GMT -5
hi bob I have little time using the AIM uhf with 845C software and I realized that there is something wrong with Zmag plot, there is any fix for this. Thanks. |
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Post by Bob on Oct 8, 2011 10:53:07 GMT -5
Version 845C had the value of Zmag offset set to 195 ohms. Set this back to zero using the Setup Menu -> Plot Offset Values ->Clear All Offsets.
--73/Bob
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Post by mbrioso on Oct 15, 2011 20:35:20 GMT -5
Hi Bob
I just clear all offsets as recommended and all fine, thanks a lot.
73
Mbrioso
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