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Charles 29-Apr-2014 9:53 PM

Bench Test RCA Preamp?
In the process of installing a first time OTA, I've run into problems. After several many times up and down the ladder, I have determined that one of the cables that came with my Antenna Direct DB8E was faulty. One problem solved. The other problem centers on the RCA TVPRAMPR-1R, it appears to be bad, is there a way to bench check it?

In addition to the Antenna Direct DB8Em my setup includes a Antenna Craft Y10-7-13, and the RCA Preamp is what was used to join the signals from both antennas to the tv input. While I figure out how to deal with the preamp, is there another widget that I can get to join the two antenna signals?

Thanks for any assistance with this!

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tomfoolery 29-Apr-2014 10:06 PM

Radio Shack has a passive UVSJ-type unit for about $10 or so. My local store had one or two hanging on the hook, and it's all I use to join my DB4e and a portable TV dipole rabbit ears unit that I had laying around, which are both in the attic. Signal strength (or quality, or some combo of the two) was actually a little better with that instead of a 2-way splitter used backwards to join them. FWIW.

teleview 30-Apr-2014 12:37 AM


You are having many troubles with your installation.

A UVSJ = UHF antenna / VHF antenna , Separator / Joiner can be used to combine the the DB8e UHF/Y10-7-13 antenna.

A reversed splitter Will Not provide good results. , sells UVSJ .

And radio shack also sells UVSJ .

Do not allow the people at radio shack to tell you a reversed splitter is the same thing.

And as the the RCA preamp.

I recommend install a , , 10G221 preamp on place of the RCA preamp.

Charles 30-Apr-2014 1:58 AM


I've checked online at Radio Shack but I don't see one, do you have a model number?

GroundUrMast 30-Apr-2014 2:10 AM

The Radio Shack UHF/VHF combiner part number is, 15-2586

Have you tested reception and fine tuned aim of each antenna, without any preamplifier installed? Simply connect the antenna to a short (50' or less) length of RG-6 coax and connect the coax to a single TV tuner... No other parts or accessories in line during the test. Once the antennas are producing reliable reception, then add the preamp to the 'equation'. Be sure to set the internal switches to 'VHF/UHF SEPARATE' and 'FM TRAP ON'.

The covers for the switches are rather small rubber plugs on the bottom panel of the mast mounted amplifier housing.

If your TV has a signal meter function, it should be useful in confirming both the single un-amplified antenna testing as well as the combined/amplified arrangement. And just to be sure, verify that the TV has been configured for 'AIR' or 'ANTENNA' mode, not the default 'CABLE' mode. The tuner will not recognize OTA DTV signals when set to cable mode.

Charles 30-Apr-2014 3:53 AM

Thanks for the several responses, it is very helpful to a novice working on his first OTA antenna system.

In the last two days I've spent about five hours going between the roof and the family room television trying to get everything right. I started with a temporary cable from the RCA Preamp directly to the TV, nothing else in the circuit. I was quite happy to find that I had 31 usable channels. The trouble started when I had the permanent cable ready and plugged it in, I went from 31 to 5 or 6 channels. I systematically tested each link in the signal path and found one bad cable, and then found that I received far fewer stations with the RCA Preamp in the circuit. If there is a way to bench test the RCA I could know for sure that it is/isn't bad and then return it as defective if that is the case. I just ordered the AntennaCraft 10G221.

GroundUrMast, when I first installed the system, I did not start with the preamp out of the circuit. The preamp was installed right away and that is when I received 31 channels. I am now running without the preamp, using the just installed permanent cable, and I'm at about 25 channels, and that is without the VHF antenna connected. I still need to fine tune each half of the DB8e, but that will be much easier now that my son is home from college and we will have someone on the roof adjusting while the other is in with the TV noting the changes.

Thanks again for all of the advice!!!

teleview 30-Apr-2014 4:30 AM


If more then 1 Tv is connected.

If the , power supply/power injector , is on the inside of the house and the power is to go to the preamp unit outside and the power is going through a splitter , then a power passing splitter must be used so the power can get out to the preamp unit.

That is why I recommended the HFS power passing splitters.

Other power passing splitters can also be used.

If a power passing splitter is not used , then the power supply/power injector must be connected before the splitter so that power can get to the preamp unit.

GroundUrMast 30-Apr-2014 4:35 AM

To test an amplifier, you need a known good signal source at a level that's appropriate for the input of the amplifier. You also need a means of testing/comparing the signal levels in and out of the amplifier.

For the hobbyist/consumer, an installed antenna known to produce reliable signal reception and a tuner with good metering functions is the only cost effective tools likely to be available. (Obviously, lab grade test gear is far too expensive.)

I have been able to accomplish a fair amount of testing and tuning of antenna systems using the metering capabilities of my SiliconDust HDHR type tuners.

If your TV has some signal metering functionality, and you perform the non-amplified test of each antenna, you'll have the signal source and metering to perform a test of the preamp.

Be very certain that you don't also have some other connection or component failure. This is why I suggest you start at the antenna, make sure it works and is aimed well, then add the next parts of your system. When too many parts are put together at once, multiple failures can be extremely difficult to isolate and resolve.

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