[ExDilbert]

The two UHF inputs would likely work to stack two antennas. Antenna models, direction and cable lengths must be identical to work properly. Stacking can increase signal strength and reliability if done correctly.

 

[thomasr]

Which (outdoor, mast) preamps are reputed to have the lowest noise?

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[rabbit73]

Which (outdoor, mast) preamps are reputed to have the lowest noise?

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Kitztech KT-200-COAX and KT-700

 

[gbswiercz]

Hello Folks,
I recently picked up an RCA TVPRAMP12E (single input) Kijiji purchase - "brand new in box" to experiment with and compare to my CM7777. Unfortunately, this has defective a power inserter (no load voltage = 8.95 V). Preamp won't power up at all (blocks all signal when installed). I changedout the wall wart (hunch), which made no difference. It's likely the VR, which on the later models looks to have changed to a CJ7809 chip. The circuitry has changed from previous version shown on this forum and the AVS forum reference data. There appears to no longer be a diode on the i/p to the VR chip.It appears to have been replaced with a choke???

Pics attached. Has anyone come up with a solution for failed power inserters for these preamps (other than return)?I was thinking of using a spare unregulated inserter I have kicking around, and using a resistor array to drop the voltage down inot the 10.5VDC range. Maybe not enough regulation for the preamp with that option. I can't return it as it is a Kijiji buy.

My soldering skills are ok, but these micro components make changout quite difficult.

Thanks and cheers....
GS

 

[Chiwaukee]

Hello Folks,
I recently picked up an RCA TVPRAMP12E (single input) Kijiji purchase - "brand new in box" to experiment with and compare to my CM7777. Unfortunately, this has defective a power inserter (no load voltage = 8.95 V). Preamp won't power up at all (blocks all signal when installed). I changedout the wall wart (hunch), which made no difference. It's likely the VR, which on the later models looks to have changed to a CJ7809 chip. The circuitry has changed from previous version shown on this forum and the AVS forum reference data. There appears to no longer be a diode on the i/p to the VR chip.It appears to have been replaced with a choke??? View attachment 11675 View attachment 11674 Pics attached. Has anyone come up with a solution for failed power inserters for these preamps (other than return)?I was thinking of using a spare unregulated inserter I have kicking around, and using a resistor array to drop the voltage down inot the 10.5VDC range. Maybe not enough regulation for the preamp with that option. I can't return it as it is a Kijiji buy.

My soldering skills are ok, but these micro components make changout quite difficult.

Thanks and cheers....
GS

This is a known problem all the way back to the RCA PREAMP1R dual input model.

It's been well-documented by others on this and other forums. I believe somebody had a cure for it but it might take a while to do some digging.

 

[gbswiercz]

This is a known problem all the way back to the RCA PREAMP1R dual input model.

It's been well-documented by others on this and other forums. I believe somebody had a cure for it but it might take a while to do some digging.

Thanks.....I have searched but haven't found any solutions.
I did find some data online for a "typical" CJ7809 regulator, which would indicate that a nominal o/p voltage between 8.55 and 9.45 volts is therange, with 9V being "typical". This conflicts with practical expereince from owners that state below 9.5 V o/p is insufficient to power the preamp. Strange that a VR with these characteristics would be choosen for the preamp if it doesn't work, but it is what it is. I think I will open up the preamp itself to see if i can see anything amiss.
Regards

 

[majortom]

When I first got the first one I ever had in 2013, I measured 95 mA drawn from 9.4 VDC output from the insertor.
I had tried to rig it up so I could eliminate the wall wart and let my antenna rotor's regulated supply power it up instead.

Signal Amplifiers (Amps, Preamps, Distro Amps)

I suspect that it will do as well as or slightly better than the RCA. It's a tiny bit quieter (0-.75 dB) on UHF and a little bit (5-6 dB) more robust on overload tolerance. Of course, it's my conclusion that the "1 dB of noise claim" missed the mark.

www.digitalhome.ca

I no longer have them here (gave em away), since as I mentioned in that post, it wasn't able to be run off of the DC power supplied by my Antenna Rotor.

 

[gbswiercz]

When I first got the first one I ever had in 2013, I measured 95 mA drawn from 9.4 VDC output from the insertor.
I had tried to rig it up so I could eliminate the wall wart and let my antenna rotor's regulated supply power it up instead.

Signal Amplifiers (Amps, Preamps, Distro Amps)

I suspect that it will do as well as or slightly better than the RCA. It's a tiny bit quieter (0-.75 dB) on UHF and a little bit (5-6 dB) more robust on overload tolerance. Of course, it's my conclusion that the "1 dB of noise claim" missed the mark.

www.digitalhome.ca

I no longer have them here (gave em away), since as I mentioned in that post, it wasn't able to be run off of the DC power supplied by my Antenna Rotor.

Thanks for the reply/info. I checked the drop box links, they are no longer active. I opened up the preamp itself, just to check for bad/cold solder joints but didn't see anything.
I contacted the original Kijiji seller, to see if he had a receipt for the RCA preamp I could use, and it turns out he has a few more in his basement (he's an OTA guy) so he will work with me to find a good one. Decent chap.
Cheers,

 

[gbswiercz]

Update....
I swapped the original 80mA wall wart for a 100mA replacement I had kicking around. I now have a functioning unit.
The 100mA may be borderline, but is working for now. Output voltage is right around 9V out of the inserter, which falls in line for the specs of the 7809 volt. reg.now used by RCA.
The preamp seems to function much the same as my CM7777, hopefully is better for overload per other posts. A side benefit is that now I am getting real channel 13, which I wasn't with the CM. Perhaps the gain of the RCA is better for that channel. It has saved me from building a dipole to recieve that station.
Regards...GS

 

[EdT586]

Any recommendations on a LTE filter in the 5-608MHz range with low attenuation and a place I can order from in Canada ? The shipping rates to Canada from US retailers is horrendous !

 

[jruano]

This summer I installed a Televes 536081 mast mount pre amp and like it so far. It has a single VHF input plus 2 UHF inputs. I tried to run 2 separate UHF antennas(pointed at different cities) into it to avoid a rotor but got lots of interference and went back to single UHF and single VHF antennas. Nice to get American stations in London Ontario even this late into fall. When American channels went thru reassigning frequencies I lost most of my USA channels but this pre amp helped get some back.

An Avant X would be a better solution for that scenario, allowing you to filter individual UHF multiplexes from each antenna.

 

[thomasr]

What do people think of the Winegard LNA-200 Boost XT vs. the Antennas Direct Clearstream Juice? The Winegard is roughly half the cost, but I'm willing to pay the extra $ if it buys a significant increase in performance.



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[rabbit73]

What do people think of the Winegard LNA-200 Boost XT vs. the Antennas Direct Clearstream Juice? The Winegard is roughly half the cost, but I'm willing to pay the extra $ if it buys a significant increase in performance.

The main advantage of the Juice preamp is its ability to withstand overload better than most other preamps. This is shown by a higher IP3, MAX Input Signal, and SFDR. The high SFDR (Spurious-Free Dynamic Range) allows it to handle strong local signals without damaging the weakest desired signals.

The best preamp for any location depends upon the desired signals at that location.

The Juice does not have a built-in FM trap, but it does have a built-in LTE filter. However, IIRC, the LTE filter is for the 700 MHz LTE signals, not the newer 600 MHz LTE signals.

 

[jruano]

High enough output levels do help avoiding overload. Just passes the problem further along in the signal chain.

 

[thomasr]

The best preamp for any location depends upon the desired signals at that location.

RabbitEars.Info

RabbitEars, where you can learn all about local, over-the-air TV channels.

www.rabbitears.info

I have a two-antenna setup: 8-bay pointed toward Hamilton (picking up CHCH plus the stuff off the CN Tower), plus a yagi pointed at Batavia NY (it's also on a rotator, though I haven't found a lot of reasons so far to point it anywhere besides Batavia).

I have the flexibility to place a pre-amp before the cable merge, or after. Because the 8-bay gets a good, strong signal all the time, I was thinking I'd put a preamp on just the yagi side to try to pull in more fringe signals.

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[ExDilbert]

I wouldn't combine the two antennas. It will potentially introduce significant amounts of multipath and interference, especially on weak signals. Placing a preamp on one antenna and not the other will potentially cause signals and interference from the amplified antenna to overwhelm those from the weaker antenna. If combining is required, I would use something such as the Avant X to combine antennas pointed in different directions. A more conventional approach would be to run separate coaxes directly into separate tuners.

 

[thomasr]

I wouldn't combine the two antennas. It will potentially introduce significant amounts of multipath and interference, especially on weak signals

Understood, but I am currently getting 34 channels with the above rig, so whether through good planning (I did spend a while calculating angles and cable lengths while designing that stack) or good luck, I seem to have a workable setup.

If I place a pre-amp after the combiner, it sounds like the Juice will do the best job managing the (relatively strong) signals coming off the CN Tower?





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