On 6/17/11 12:00 PM, [email protected] wrote:
Date: Thu, 16 Jun 2011 19:56:28 +0000 From: George R Allen<[email protected]> To:"[email protected]" <[email protected]> Subject: [FlexEdge] Calibrating to WWV, technique for Freq Measuring Test, with the F5K Message-ID: <[email protected]> Content-Type: text/plain; charset="Windows-1252" I received the attached info from from Jim, W4GB that I wish to share with the group. I have used this technique for frequency measuring using a Wavetek 5120 Synthesizer (equivalent to PTS160). This is basically the"hetrodyne method" for measuring frequency. I am not saying this is preferred or the best way. Just a way that works for me. When using the synthesizer as the hetrodyne source, I use AM as the mode and observe the beat on the "Panascope" on the F5K. George K2CM ---------------------------------------------- From: Jim Ferguson [[email protected]] Sent: Wednesday, June 08, 2011 2:01 PM To: George R Allen Subject: Frequency Zero beat George, You can do all of the things you are doing now just a little bit more simply. This is how I calibrate my 5000a to a WWV frequency, and it will work exactly the same with whatever frequency the receiver is tuned to. I will show you how to use the already built in PanaScope mode, and a filter as narrow as 10 Hz if you like. I use 16 HZ. Here is how I setup to my frequency cal mode. No external scope required. Since the beat note is FAR Sub-Audible, I don?t worry about hearing anything, it?s all visual. 1. Go into Setup/Display/ Scope Mode; Adjust the sweep time to 10,000 uSec. That sets the end-to-end sweep time to 10 seconds; that?s handy for arithmetic in your head. 2. Exit setup 3. In the radio MODE selection: i.e., LSB, USB, AM, etc., Select DSB 4. In the filter bandwidth, Select 16 K, Place the mouse cursor on the 16K box, and right click.; a sub-menu opens; left Click on CONFIGURE 5. In the Configure box we will edit the 8000 in both the UPPER and LOWER to single digit 8, as in Hz. (You now have a 16 Hz bandwidth filter) then, Up in the NAME box, edit K to HZ; close the configure box. 6. Now when you choose the DSB mode, you will have a 16 Hz filter available, that narrow B/W wipes off noise, and gives a clean scope trace. 7. In the Display Mode Selection Box, normally set on Panadaptor, cursor down to PanaScope, left click. You now see the Beat-Note on a 10 second scope below whatever frequency you choose displayed on the Panadaptor. Note that you can see phase ?hits? due to ionosphere anomalies, lightning, etc. Ideally, you would see a smooth Sine Wave for best calibration. If you click on the WWV sequence, 2.5, 5, 10, 15,20, for frequency selection, you will see what I mean. 8. I think you probably already know how to go into the DDS expert mode and adjust the offset, or to use the auto-calibrate mode for the internal frequency reference. 9. In mid-afternoon, between here in Florida, and Bolder, Colorado, I frequently can get 15 or 20 MHz within ? sine wave showing over the entire 10 second sweep length. I have to go in to the offset number and edit it in single digit steps. The normal increment of 10 is way TOO much. 1/4 of a full cycle, over 10 seconds sweep is within 1/40th of a Hz. Of course, it will drift off that stability over time, but I?m sure I?ll always be within ? Hz from day to day. 10. You can go to 4X screen magnification to see really close on the Panadaptor. As Gerald Youngblood said years ago, and I paraphrase, ? the 5000A is a box of test equipment with an Amateur radio attached.? Isn?t this FUN? Jim Ferguson, W4GB
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