Sadelco FS-3 Signal Meter

[EscapeVelocity]

Im wondering if an old Sadelco signal meter would be good enough for me....like the Sadelco FM-3 shown below. A similar Sadelco model was referenced in Salvati's book TV Antennas & Signal Distribution Systems.

The Sencore 1454 and 1456 Spectrum Analyzers are expensive! Lucky Trip!

Anybody have any experience with these?

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.

 

[rabbit73]

EV:
Glad to hear that you like Salvati's book; it's one of my favorites.

Do you mean FS-3?

I have found that an old TV field strength meter can be very useful when comparing antennas. The newer models are called a signal level meter (SLM). The reading of a digital signal on an old FSM will not be exactly the same as the reading on a signal level meter designed for digital signals, because the analog meter is designed to measure the peak value of the signal. The meter for digital signals is designed to measure the average value of the digital signal.

When I use my Sadelco 719E meter to measure a digital signal I turn on the audio to listen to the carrier. Its a rushing noise that sounds like white noise (or intercarrier noise between FM stations if the tuner does not mute). The digital signal nearly fills the whole 6 MHz channel, but I fine tune the meter to about 1/3 or 1/2 the channel width up from the bottom to avoid the pilot carrier at the lower end, which would give a false reading.

I often also have my Apex DT502 CECB connected with a splitter and watch the signal QUALITY bar when aiming an antenna because the best quality signal isn't always at the same azimuth as max signal strength because of multipath reflections. This is another example of signal quality (related to BER) being just as important as signal strength with digital signals.

If you read the Aussie DTV forums (they have had a longer experience with their DVB-T digital, especially with many antennas in the outback) you will see it said that you shouldn't hire an antenna installer unless he uses a BER meter to aim your antenna.

How closely to two meters agree depends upon the individual calibration of each meter. I have compared a Sadelco 719E analog meter with a Sadelco DisplayMax 800 designed for analog and digital signals and they are, by chance, fairly close:
Old TV field strength meter any good? - AVS Forum

But, when comparing antennas, aiming an antenna, or finding the best location for an antenna the absolute calibration is not as important as the linearity of the meter when making comparisons. The linearity can easily be checked by inserting the 20 dB attenuator to see if the new reading is 20 dB lower.

Actually, I prefer to use the needle of an analog panel meter to the digital readout meter when aiming an antenna.

 

[EscapeVelocity]

Hey thanks for the link to ground already covered rabbit73!

I have a signal quality meter on my Zinwell 970A....and I have the Signal Strength meter on it as well. I guess I could just use that for comparative testing....but was hoping to get something a little more sophisticated.

I need to get a set of attenuators too. Been putting that off.

I would like to get a strength meter as well. I am very interested in the Sadelco's. And I see that you are a fan of them. Good to know I can use them. I want to use them to do relative testing of antennas, specifically the 8 bays, especially the 4228HD and the xg91...and compare them to my Kosmic SuperQuad Tune-A-Tenna.

I really should spring for one of the Sencores though.

PS- I think you are right the FS-3. Those old Sadelco's look sweet, dont they!

 

[rabbit73]

EV:

I have a signal quality meter on my Zinwell 970A....and I have the Signal Strength meter on it as well. I guess I could just use that for comparative testing....but was hoping to get something a little more sophisticated.

I like the CECBs with dual signal bars and have used the Zinwell 970A, the Sansonic FT300A, and the Apex DT502. My favorite is the Apex because of its wide range and consistent readings:
AVS Forum - View Single Post - The Official AVS Antenna Topic!

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. If you are going to use an older version called a field strength meter (FSM), you might find this post about dBm, dBmV, and old FSMs helpful:
AVS Forum - View Single Post - Antennas, rotators, boosters/preamps... for wide-band VHF/UHF

When you are reading the dB scale on an old SLM that has a panel meter with a needle, keep in mind that the higher negative numbers (below 0 dBmV) are to the left, instead of to the right as for the positive numbers above 0 dBmV, especially when you are interpolating between the meter divisions for tenths of a dB. Also, check the built-in attenuators to be sure that you are on the correct scale (that's the one that messes me up sometimes).

Good luck with your antenna measurements and

Best regards,
rabbit

 

[FOX TV]

Innovative

EV:
Glad to hear that you like Salvati's book; it's one of my favorites.

Do you mean FS-3?

I have found that an old TV field strength meter can be very useful when comparing antennas. The newer models are called a signal level meter (SLM). The reading of a digital signal on an old FSM will not be exactly the same as the reading on a signal level meter designed for digital signals, because the analog meter is designed to measure the peak value of the signal. The meter for digital signals is designed to measure the average value of the digital signal.

When I use my Sadelco 719E meter to measure a digital signal I turn on the audio to listen to the carrier. Its a rushing noise that sounds like white noise (or intercarrier noise between FM stations if the tuner does not mute). The digital signal nearly fills the whole 6 MHz channel, but I fine tune the meter to about 1/3 or 1/2 the channel width up from the bottom to avoid the pilot carrier at the lower end, which would give a false reading.

I often also have my Apex DT502 CECB connected with a splitter and watch the signal QUALITY bar when aiming an antenna because the best quality signal isn't always at the same azimuth as max signal strength because of multipath reflections. This is another example of signal quality (related to BER) being just as important as signal strength with digital signals.

If you read the Aussie DTV forums (they have had a longer experience with their DVB-T digital, especially with many antennas in the outback) you will see it said that you shouldn't hire an antenna installer unless he uses a BER meter to aim your antenna.

How closely to two meters agree depends upon the individual calibration of each meter. I have compared a Sadelco 719E analog meter with a Sadelco DisplayMax 800 designed for analog and digital signals and they are, by chance, fairly close:
Old TV field strength meter any good? - AVS Forum

But, when comparing antennas, aiming an antenna, or finding the best location for an antenna the absolute calibration is not as important as the linearity of the meter when making comparisons. The linearity can easily be checked by inserting the 20 dB attenuator to see if the new reading is 20 dB lower.

Actually, I prefer to use the needle of an analog panel meter to the digital readout meter when aiming an antenna.

If I didn't have access to the equipment I do, then I would be envious. It doesn't matter how you determine it, just be sure to determine it. Measure twice, cut once..Nah that one doesn't belong does it?:grin:

 

[rabbit73]

If I didn't have access to the equipment I do, then I would be envious. It doesn't matter how you determine it, just be sure to determine it. Measure twice, cut once..Nah that one doesn't belong does it?:grin:

Thanks, I take that as a compliment. My goal has been to find relatively inexpensive tools that can be easily used by the average guy to help solve his reception problems.
More than once I have seen a post that goes like this:

I live less than 5 miles from the towers and my antenna is in the attic but I don't get any signals. What's wrong?

Well, if he could find one, a used SLM would be helpful. It wouldn't be very expensive but he would have to learn to use it.

But he doesn't have one or a TV with a signal diagnostics screen, so there I am, staring at the screen that shows his tvfool report with the top dBm pwr figure in red (overload warning) and wondering should I tell him to try an attenuator because his tuner is suffering from overload because his antenna is behind vinyl siding, or should I tell him to temporarily set up an antenna outside because his attic antenna is behind aluminum siding.

 

[EscapeVelocity]

Well, I missed a nice Sadelco FS-3 and that is what I ultimately want to get, but I picked up a Sencore FS134 just now. We'll see how that pans out. VHF/FM/UHF. Battery operation (only?) 9 C cells.

 

[salemtubes]

I need to get a set of attenuators too. Been putting that off.

I purchased this variable attenuator a few years ago on eBay:

I don't know how often they come up on eBay, but you might want to keep your eye out for one.

 

[EscapeVelocity]

Yeah, those step attenuators are not very common. Thanks for the pic and info! RMS Electronics also made something similar but different.

Ill definitely be looking for one of those!

 

[EscapeVelocity]

Are those standard F connectors or are the BNC?

 

[salemtubes]

Standard F connectors.

 

[ProjectSHO89]

Those are F-connectors. 50 ohm impedance would be BNC. Plus, you can see the threads and BNC connectors don't have threads.

I need one of those.....

 

[Tower Guy]

I picked up a Sadelco Display Max 800 on ebay.

Sadelco, Inc. - Signal Level Meters

It is specifically rated for digital signals, which may be either QAM or ATSC.

There are two of them on ebay right now, here's one.

Sadelco DisplayMax 800CLI - eBay (item 180453803902 end time Jan-16-10 19:00:11 PST)

The CLI model isn't needed for OTA, but the option does not hamper its operation with an antenna.

 

[EscapeVelocity]

Those DisplayMax 800's seem to go for quite a bit less than the Sencore 1454's and 1456's.

Nice.

 

[EscapeVelocity]

Here is the Online Old CATV Equipment Museum.

Some nice units there including a Sadelco FS-3 which seems to be a bit different configuration than the one pictured on the OP of this thread.

Plus the Sencore FS134 and others by Texscan and WaveTek.


Lots of great stuff on that site. For example, here are Vintage Baluns. Here is the Home Page.

 

[EscapeVelocity]

The WaveTek SAM I looks like it might be a winner. Nice aesthetics too.

 

[EscapeVelocity]

I really wish I would have won that FS-3 the other day!

The Sencore FS134, just doesnt look as user friendly.

 

[salemtubes]

Those are F-connectors. 50 ohm impedance would be BNC. Plus, you can see the threads and BNC connectors don't have threads.

I need one of those.....

Be careful when looking at 'em; there are 75 Ohm Kay attenuators with BNC connectors.

 

[rabbit73]

One of my 75 ohm attenuators has BNC connectors. I'm using Pomona 6779 BNC (m) 75 ohm / F (f) adapters that seem to be OK.

http://www.pomonaelectronics.com/pdf/broadcast/2153555_w.pdf

 

[EscapeVelocity]

Aparently the new DigiAirs now have a switch for NTSC to ATSC which makes them useful for the modern signals. Shame I got an old unit.