Winegard AP-2870 pre-amplifier

Pete Higgins

In a previous post I alluded to the fact that I couldn't lift the TV antenna array & tower by myself. The 24' tower (3-8' sections) is mounted to my patio roof ~9' AGL. It is hinged so it tilts over into my back yard. I bought a small electric winch and erected a 16' winch mast and ran the winch cable to the second section of the tower (at the 16' level). The winch pulls the tower up so fast its scary! Next week, I am going to switch over to a double-line pull to cut the pull speed in half. Attached are some pictures showing how I am solving the lift problem.

Attached Images

	Winch.jpg (76.3 KB, 28 views)
	Winch Mast.jpg (57.9 KB, 26 views)
	Winch Mast Top 2.jpg (17.7 KB, 26 views)

Pete Higgins

FYI ALL,

I sent an email to Antenna Craft last night and they replied with; "The maximum input level of the 10G221 is ~110k uV VHF and ~90k uV UHF. Even with notch filtering, shooting through two transmitters @ 294 degrees will be a challenge. Therefore, keep amplifier gain to a minimum and be selective on your antenna’s physical location."

Winegard lists the maximum total input for the AP-2870 as 110,000 μv VHF, 93,000 μv UHF. (Or basically the same.)

Winegard lists HDP269 High input Pre-Amplifier @ 350,000 μv (combined)

I may have to connect both my antennas to a UVSJ. Then connect the NF-471 trap between the UVSJ and the HDP269. I had the tower up today with just the Y10-7-13 connected to the AP-2870 VHF input and got channel 7.1, but lost channels 9.1, 11.1 & 13.1. Couldn't get anything with it pointed to San Diego (8.1 & 10.1).

IDRick

Hi Pete,

Thanks for reporting the maximum input levels for the 10G221! Interesting that it is similar to Winegard AP 2870 specs (and most other Winegard preamps with exception of HDP269).

Best,

Rick

Pete Higgins

Reconfigured the winch mast pulley for a double line lift and that helped slow down the rate of tower decent and mitigated almost all of the bouncing when stopping it. Also installed 6 guy wires w/turnbuckles to the top two sections just to be on the safe side. The back two have hooks on the ends that attach to the eye-bolts so it only takes a couple of minutes to release them and lower the tower.

The AP-2870 turned out to be a real bust. It overloaded so bad that I only got a couple stations. One from San Diego with the antenna array pointed 180 (i.e. 114 degrees away from my -15.6 dBm UHF station). Of course I got KVCR the -15.6 dBm PBS station no matter where I pointed the array. I could get some LA stations but usually not the same ones repeatedly. Thought I might have an intermittent cable. Swapped cables with the same result. It didn't seem to matter if I had the channel 26 notch filter installed on the 91XG or not.

Next I installed a UVSJ and the Winegard HDP-269 that worked with my old CM4228. It worked a little better with the notch filter installed on the 91XG than it did without it but it was evident that in either case I was still overloading.

I tried the PCT-MA-B1010-1P 10 dB drop amplifier (installed at the base of the tower) that I used with my old CM4228 and started getting most of the channels I had before. Had a few missing channels and drop-outs because the signal was just to weak for the tuner but everything else stayed consistent.

Encouraged, I ordered a new PCT-MA2-M single port 15 dB drop amplifier to mount up at the antenna array and a PCT-MA-B1015-4PN
(4 port @ +7dB/port) to serve as a distribution amp. These are really neat little amps. They come in a weather-sealed housing,
can be local (through a separate 'F' input) or remote powered
(through the signal coax) and are designed to work with cable signals that are typically between 0 & 10 dBm without overload -and reportedly have a 2.7 dB noise figure.

As soon as the MA2-M arrived I dropped the tower (boy I'am glad to have that winch!) and installed it through a M-M barrel connector to the UVSJ. Powered it up through a Summit Source procured ASKA PI-10 Power Inserter and nothing. Turns out the power injector was shorted. Even after ordering $297.77 from them, Summit Source wouldn't replace a defective $1.99 part. Substituted one of the Winegard power inserter's and my signals almost broke clean.

Installed the 4-port distribution amp in the garage and I've got back 122 of the 123 channels I found with the old CM-4228. Of course I eliminated almost all pixelation and have a much better viewing experience.

Thanks for all the interest and help with my project.

Pete Higgins

I had exclusively used cable TV since I bought my house new in 1980. A few months back I came across this forum and was fascinated by all the posts. I dug out a 40+ year old Channel Master CM4228 8-Bay Bow Tie to see what I could receive. Encouraged, I set about designing the system shown on the attached .jpg file. I went with the recommended Antennas Direct 91XG for UHF and an Antennacraft Y-10-7-13 for VHF High. I also added a Winegard HD6065 10 Element YAGI to the array for FM.

I consistently receive 122 OTA digital channels (including sub-channels) and several full & low power analog channels. Channels are clustered in Twentynine Palms, CA (74.86° @ 24.82 mi), San Diego & La Jolla, CA (168.71° & 180.78° @ 88.05 mi & 76.58 mi respectively) and Los Angeles, CA (292.40° @ 51.74 mi). I also regularly get several stations from Tijuana, Mexico (174.6° @ ~100.00 mi).

When I first started, I didn't realize that there was one strong FM (-13.4 dBm) and another strong UHF TV station (-15.6 dBm) broadcasting from a mountain 3.5 miles from my house and in line with the LA stations. With the new antennas, these two stations put all the Channel Master & Winegard pre-amps I tried into gain compression (including the Winegard HDP-269) -hence the use of cable TV “drop amplifiers” @ the array. Due to my tower location and the way my house is laid out some cable runs exceed 200' so amplification at the signal source was a definite must. I couldn't find a UVSJ that passed power through both ports, so powering the array amps through a separate coax (500' of RG-6 for $35.00) seemed like an economical solution with the added advantage of eliminating UVSJ loss.

As a side benefit, all the attic crawling & roof/tower climbing helped get this 69 year old body back in better shape.

Thanks to all who helped with suggestions, information and encouragement.

Attached Images

OTA TV & FM Wiring Diagram Pictorial.jpg (101.6 KB, 31 views)

Normster

Hi Pete, I see the diagram but have a little trouble making out the details. Do you happen to have a higher quality photo or a different format file available? I would love to base what I need to do off of your setup.

Pete Higgins

Normster,

I sent the .jpg diagram of my OTA TV setup to your email address. It should print to a full 8.5 by 11 inch piece of paper. If you are working in Windows, just "right click" on the file and select "open in Paint". From their you should be able to zoom in or print.

Pete

JB Antennaman

The problem with some educated people is that they do not ask for help, but asks for guarentee's - so they can ensure that they can get what they want before they plunk down the dough to get it.
The bottom line is that the coax should have been ran from the antenna to the pre amp to the inside of the house and then split 3 ways or what ever.

Even using RG 11 - it shouldn't have been much of an issue to get the system to work.
Unfortunately, what the OP tried to do wasn't sound in theory.

The stations were already gettable, the problem was the loss in 300' of coax.
The distribution amplifier solution would have been a good start, as long as the op didn't try to use two amplifiers at the same time.

The filter was another good solution.

The only viable solution was to buy a better 4228 and a new pre amp and install all new coax of a known loss factor and not have mismatched components.

Coax goes bad, I don't care if you keep it inside of the house and it looks like new. At some point - the OP threw away the baby with the bath water.

I would bet that if he would have posted a street level address at the onset, we could have eliminated half of his posts and discussions.
And the bottom line is - that with a little effort, he should have gotten back all of his digital signals he received before - not comparing apples to apples - if he was trying to get back all of his analog signals.

And with a good TV fool report - probably would have found a couple of channels that did not exist before - especially if he experiences some winter tropo and does some searching with the rotor and tuner.

__________________
Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.

Pete Higgins

JB,

Sorry that my implementation upset you so.

This forum got me interested to see what I could receive at my location so I hooked up a very old 8-Bay Bow Tie UHF antenna I'd had laying outside for 32 years. I got a PBS station crystal clear and some Los Angeles stations that were watchable but would pixel-ate. I grabbed the only amplifier I had available (a +10 dB PCT-MA-B1010-1P cable drop amplifier), ran an extension cord up to the roof to power it and started receiving some of the LA stations more reliably (even some Hi VHF channels occasionally). At this point I had no idea that there were strong stations 3.5 miles from my house and only offset 2 degrees in bearing from the LA stations.

As a youngster in the 50's I worked in a TV shop and helped install numerous TV antennas in and around La Jolla, CA. In those days, we used Bow-Tie, Log-Periodic & Yagi's. Almost all installations were on guyed push-up masts with 300 ohm ladder line or twin-lead for the transmission line. The higher-end jobs included a rotor and sometimes a tube-type pre-amp. I fully understand that pre-amp's don't increase the signal a given antenna captures but only serve to amplify what is available at the antenna terminals to overcome cable/splitter loss (and in some cases boost the signal enough to work with a poorly designed tuner).

I replaced the drop amp with a Winegard AP8275 that as soon as I powered it on was obviously going into gain compression. I ran a TV Fool report and discovered the strong PBS station 3.5 miles away. I ordered a Winegard HDP-269 and while it didn't work any better than the drop amp, it didn't overload and I could power it through the coax so it made for a much cleaner installation.

The technology has changed a lot in the last 50 years. If it helps any, recognizing this, I asked for information selecting a pre-amp. from the folks on this site who were obviously way more current than I was. With IDRick's help, two days after my first post I did provide a link to the TV Fool report for my location. I certainly didn't expect a guarantee but educated or not I do believe it's a good idea for people to ask questions “so they can ensure that they can get what they want before they plunk down the dough to get it”. I received a lot of good feedback that I am still very grateful for.

Encouraged, I ordered both a Y-10-7-13 & 91XG plus a Winegard AP-2870 for a permanent installation. I also ordered a 55 dB notch filter centered on the PBS station in hopes it would prevent the 2870 from overloading on UHF. While waiting for that order, I ran new RG-6 w/Channel Master compression 'F' connectors from the tower to all household outlets. I have 5 computers with tuner cards and multiple TV's connected through well over 200' of coax so a distribution system was always planned.

With the new array in the air all of the TV antenna preamp's were put into gain compression, including the HDP-269, whether or not I had the notch filter installed at the antenna. The +10 dB PCT drop amp (which I could now power through the coax using the HDP-269 power injector) still worked like a champ.

The mountain that I point through to LA is lined with towers. I know for certain that I shoot through one strong FM (-13.4 dBm) and another strong UHF TV station (-15.6 dBm). What I don't know is how many other commercial, analog cell phone, public safety and amateur repeaters that fall within the bandpass of these pre-amp's are combining to cause my gain compression problems. But I do know that you can't argue with success. The drop amps work where the TV pre-amp's didn't.

While using F-71 couplers instead of coax between the antenna and the pre-amp marginally reduces loss incurred in a length of coax it was solely done as a convenient way of mounting the pre-amps. at the antenna. In a similar vein, installing the amplifiers ahead of the UVSJ boosts the precious OTA signal before it incurs the .5 to 1 dB of UVSJ loss. Unfortunately, I couldn't find a UVSJ that would pass power to the pre-amps. Fortunately, the drop amps provide an additional power input separate from the signal path. I had a 500' roll of RG-6 and was running new cable anyway so including an additional run for power was easy.

The use of two amplifiers at the same time is the result of empirical testing (and good design practice). Stations that would pixel-ate or freeze with just +15 dB of amplification between the antenna and the tuner were solid with the addition of the second +8 dB /leg amplifier. Cascading amplifiers in electronics is common practice. Think of the IF strips in receivers and the power output stages in transmitters. They both typically contain cascaded stages. Admittedly, one must insure that the output of a previous stage doesn't overdrive a subsequent stage. Cable drop amplifiers are designed to work with cable input signals that typically range from 0 to well over 25 dB so they are not prone to overload like the more commonly used TV antenna pre-amps. The ones I am using reportedly have a 2.7 dB noise figure which compares favorably with the better commercially available TV pre-amps. Finally, since this design went up, I am able to receive all the major stations from Twentynine Palms (~25 Miles away), LA (~ 58 miles away), San Diego (~87 miles away) and frequently Tijuana, Mexico (over 100 miles away) as well as a number of low power analog stations & translators.

Hopefully, understanding how my implementation evolved will sooth your ruffled feathers.

JB Antennaman

It's cool..

We mostly get people on this forum - who doesn't know anything, that wants guarenteed reception, but doesn't want to give a street level address - like the boogie man is going to get them or something.

I had a similar experience with a friend in Waynesboro Va....
He is a microwave radio repairman and engineer.
He wanted guarenteed reception, but he didn't want to turn his antenna when he wanted to watch a station from a different direction.
The WVIR signal atop the mountain 9 miles away, was causing all kinds of havoc
Even after I suggested a antenna combo - he kept what he had and just added a pre amplifier - since his bit the dust.

A huge VHF antenna with little UHF in a market saturated with UHF only signals - doesn't make much sense to me, but the overload from the local FM stations - if you open the trap would cause more problems then it would solve.

I have learned that with intelligent people - to just give them the information and let them do what they are going to do, and not try to teach them anything.

Experience is the best teacher.

I know people with college degrees, with years of experience working in the field of electronic's - teaching, who when given a simple problem, cannot solve it - because they do not know how to apply the knowledge they posess..

Glad that it all worked out for you.
You must have a lot of stuff in your junk box and a lot of time on your hands to invest all that money into terrestrial television.

I hope it was all worth it.
Jerry

__________________
Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.