Yes, Steve, I also like the Sadelco meters. Even the older meters that were designed for analog signals are entirely adequate to aim an antenna, to locate an antenna in the best spot, or to compare antennas. Actually, I prefer the needle of a panel meter rather than a LCD meter to peak a signal.
A caution: stay away from the late used Sadelco analog meters like the 7600 or FS-5 because the audio has a true FM detector which isn't much help when you are trying to listen to a digital signal when tuning; the noise of the digital signal blends with the background noise. The older Sadelco analog meters used AM "slope detection" of the audio which makes the digital carrier stand out from the background noise. I found this out the hard way.
I want to make a correction to my post #4:
.....Other than a spectrum analyzer, the best instrument for comparing antennas is a signal level meter (SLM). There is one disadvantage to the newer scanning type meters like my DisplayMax 800: the display scan takes a long time before it gives the dBmV value which makes aiming an antenna tedious when in the scanning mode....
I found out from the Sadelco tech that the DM800 can be used to peak antenna aim:
"Regarding the Dmax800: keep in mind the "F1" soft key to allow a single freq reading at the center of the channel; although its not corrected for a digital signal, its a valid "relative" dB indication that updates about 5x per second. This is a good mode to be in for initial peaking of the antenna, then press the F1 again to get the scan and correct power reading."
The meters that I am presently using are a Sadelco 719E, DisplayMax800, and a DisplayMax 5000. I bought the 719E when I retired from the government in 1988, and the other two were given to me by my wife. I have a VERY understanding wife who tolerates my antenna experiments.
I tried the
Perfect Vision DigiAir last year, but it was calibrated to NTSC signals and so it registered really low out of the meters range really to make it useable/readable. Shame because that would be a great little device if recalibrated to ATSC.
So Im wondering if you can switch to a lower reading on the analog meters with these analog Sadelco units.
I haven't had any experience with the newer Digiair Pro2 meter, but it has received three favorable reviews on the Solid Signal site. There is a manual there available for download, but I'm not sure that it is the correct one for the latest meter; it says: "All Modes are in NTSC MODE, Graphics reflect Europe version and are for example purposes only."
There are three manuals that can be downloaded from the
importers site. Go the bottom of their home page and click on Manuals which should take you to
their equipment manuals page which shows a choice of:
DigiAir Pro (DIGIAIR PRO 2004)
DigiAir Pro 2.1 (DIGIAIR PRO 2005)
DigiAir dB 1.0 (DIGIAIR dB 2001, has ATSC in upper right corner of display)
I don't know which one of the above is the right manual for the model sold by Solid Signal (my guess is the 3rd one):
Perfect Vision DIGIAIR PRO 2 Off-Air Digital and Analog TV Signal Meter (DIGIAIR DB) - Perfect Vision - DIGIAIR PRO2 -
To answer your question about lower readings:
Once you switch out all of the meter attenuators, you can't go any lower.
When I am doing sensitivity tests of tuners near the "digital cliff" using an attenuator and a splitter (to feed the tuner and the SLM), I find it necessary to insert a preamp between the splitter and the signal level meter (digital or analog) to be able to measure weak signals. I then subtract the preamp gain to obtain the true reading in dBmV. The noise figure of the preamp doesn't affect the tuner, because it isn't in line with it.
Keep in mind, however, that if you are measuring a very weak signal and you also have a very strong signal on the coax line, there might be a problem with preamp overload. I don't have that problem when I'm measuring tuner sensitivity, because I start with a strong signal and attenuate it before it gets to the splitter.
The specs for the Solid Signal meter say "Input level: 25-100 dBuV." This is equivalent to -35 dBmV (-83.8 dBm) to +40 dBmV (-8.8 dBm). This should take care of most of your measurements except for the very weakest signals; the NTIA CECB tuner sensitivity spec is -83 dBm.
My Sadelco 719E (similar to the FS-4) will measure down to about -35 dBmV, where the meter scale divisions become crowded. My Sadelco DM5000 measures digital signals down to about -23 dBmV before giving an under range message; for analog signals about -30 dBmV which reflects the analog VS digital correction factor of 6.8 dB in the meter. The DM800 also gives an under range warning below -20 dBmV, but will read lower when you press F1 for a single frequency reading as mentioned above.
