When doing precision calibration of TV broadcast carrier, we would monitor WWV frequency on an HP device with a chart recorder over a period of a couple days. There was a very minor sinusoidal frequency drift caused by daily atmospherics. We had to find the average of the daily drift in order to predict the exact WWV frequency. Time consuming, but accurate.
Great video, Len - thanks! I just did your calibration procedure on my mod'ed 815. I live in New Mexico, and was able to hear a decent WWV signal today on 25 MHz, and everything went fine. I only needed to change the factory RefDAC setting by two to get within 1 Hz at 25 MHz. I don't think folks who have factory stock units will be able to get as close with this method, though. Maybe for them, coupling the 815's 10 MHz output loosely to a receiver tuned to the WWV signal at 10 MHz, and adjusting the RefDAC setting for an audible zero beat might work. Or connecting a short antenna wire to the TG output, set to zero span at 25.0 MHz, and zero beat with WWV? Cheers, Chris
Good Morning! KDORC, Would you like to know where the Rigol network of technical assistance in the United States of America is located ?. Do you have an email so I can ask you some questions about the DSA815TG? Very grateful and I await your contact. Thankful. Alandex Santos.
I just installed the 00.01.19 firmware and also found the keystroke sequence no longer works to access the service menu. Maybe it has been changed. Does anyone know how to access the service menu with the newer firmware?
Hi Doug, I think I found it on EEVBlog (Dave Jones' channel). I believe that it only works on older 815s. Rigol changed the bootloader so that newer units can't be hacked using the method that I used.
