Established Feb 2008... updated 28 May 2017
The goal of this site is to be your "one stop" source for authoritative information regarding the Channel Master 4251. The CM 4251 is (was) a 7 foot diameter parabolic UHF TV antenna that is widely accepted as the most powerful production consumer UHF TV antenna ever manufactured. Several other companies did make competing models and there are some UHF antennas available today that can come close to the 4251's performance, however the 4251 pretty much remains as the unofficial "king" of UHF TV antennas. The 4251 is no longer available. This is unfortunate because now that HDTV is upon us there is a renewed market for over the air TV reception (and hence the need for powerful antennas). The 4251 is also highly sought after by those who do DX work (DXing is a hobby where people try to receive stations from far away places). This page is dedicated to the Channel Master 4251 and it will contain photos, technical data and historical items!
A Vintage Channel Master 4251 installed Jan 2008 for HDTV reception!
I got my Channel Master 4251 in 1986. I had wanted one for many years prior to that, but I lived at home at the time and my father said "no" to an antenna that big being on the roof (we did have 6 other antennas on the roof at that time so in retrospect I can understand his decision). In 1986 I moved to an apartment (actually it was a 3 family house) and the landlord said "do what you want" with regard to antennas (hooray)! The downside was that the place I lived in was in deep narrow ravine and I knew reception to the west (where most of the stations were) would be nil even with the 4251 (even from the top of the roof it would be pointing into solid rock). Undeterred, I bought my 4251 from JAN Electronics in New London, CT. At the time the cost was around $155. I had a Chevy Cavalier so I had to do a lot of preparation beforehand to get the antenna back to my house (around 20 miles away). What a site having that 4251 box strapped to the side of the car, it was almost as long as the car itself!
I installed the 4251 on the roof (the house had a roof with a small watch tower on it so access was as simple as it could be). As expected my reception was limited due to the valley I was in. Nonetheless I was able to get a watchable picture on a Long Island station (channel 55) that would only put a "change in snow" on the TV with a Radio Shack U-100 UHF antenna! I did not live in that house for too long (other people that moved in were slobs, brought cockroaches in, etc) so I moved to another about 1/2 mile away. This house was in a much better location for receiving channels, but the problem was that the landlord did not want any antennas on the roof. So, I set up the 4251 in the attic (see picture below). Not the best situation, but I was able to get stations I wanted to see (the downside was that I had to go up to the attic to rotate the antenna manually). In the summer of 1988 I had the opportunity to buy my first house. Once I moved in one of the first things to be installed was the 4251! This time I had a great shot to the west, north and south but a marginal shot to the east. It was in this location that I logged the most reception. I could get at least a dozen stations with perfect signal and about another dozen or so that were clear enough to watch. I lived in this house from 1988 to very early 2002. The 4251 was a fantastic asset. I had it mounted on an extremely strong mast with a rotor bearing and extra heavy duty guy wire mounts. I also had a preamp on the 4251 to overcome line loss (I used RG-6 cable). I had another UHF-VHF combo antenna mounted below the 4251 and I had it rigged so that I could switch between antennas using an RF switch (to compare reception). The 4251 could bring in watchable reception on stations that the combo antenna would only barely show! What a fantastic antenna this was. There was one TV tower (Channel 26) that went in only about 5 miles from me. With the 4251 the signal was so strong that it overloaded the TV (I had to use the smaller antenna to watch this station)! In early 2002 I moved to a new house. This new house was nicer with a lot of land, however once again it was down in a valley. I took the 4251 with me when I moved. The new house did have a UHF-VHF combo antenna on the roof and due to the bad location I could only barely get channels that I used to have perfectly clear. I did not install the 4251 on this new house but instead put it in storage in a barn at my parent's house. Something told me "do not toss this item out, you waited too long to get it and you might want to use it again someday....". That voice in my head proved to be very wise.
Enter 2008. HDTV is now here and soon to be the only broadcast available. My brother was gaining interest in buying an HDTV. He did not know that HDTV broadcasts were available for free (networks anyway) over the air. He asked about the TV antenna we had on the roof at that time (it was a suburban UHF-VHF combo unit). I said "I have the perfect antenna for that!" Long story short, the 4251 was taken down out of the storage in the loft, refurbished and installed once more on the roof (the picture at the top of the page shows this installation). The 4251 lives on! A neighbor even called to ask "What's that big antenna for?" Most people don't notice the average TV antenna, but when they see a 4251 they know it's not a common site. Those who DO know what a 4251 is say to themselves "there is a serious TV enthusiast living there" when they drive by and spot a 4251!
2011 Update: The 4251 is down once again... it's on my 3 season porch for the moment (safe from the worst of the weather). My brother got HD cable so the antenna was seeing not as much use, plus we needed to do some roof work anyway. I do plan to install the 4251 on my current house. I am thinking about a tower for it however, so I am currently researching options. When I have more time I will take more detailed photos and measurements on it (photos of the feed have been added below per request of a visitor who needed info on rebuilding one).
The 4251 is a powerful antenna. It has a lot of gain
and a narrow beam. I've used a number of UHF antennas over the years but
none can match the 4251's ability to rake in a signal. I would find a
weak UHF reception on a channel and then turn the rotator to zero in on the
station. As it turned the snow would come and go but once the signal got
on the main lobe of the 4251's response WOW did it make a difference! The
beam is fairly narrow so you do have to aim the 4251 fairly carefully for weaker
stations. As mentioned above, the 4251 can pull in a watchable (analog)
signal where other antennas only show changes in the pattern of the
snow!
A visitor to this site (Bob Seaman) wrote to me and provided the following information:
I am a member of the WTFDA (Worldwide TV/FM DX Association). I have been a member since 1983 and was interested in TV and FM DXing for many years before that. One of our members posted a link to your site recently on our repeater list. I do know the story behind the demise of the CM 4251. Another member of the WTFDA, Rich Wertman from Lockport, NY has a business that does antenna installations for homeowners and he also does installations for businesses such as hotels, motels, apartment buildings, etc. Ever since CM stopped making the 4251, in 2001, he has been checking into having someone remake a parabolic UHF antenna. Rich contacted Antennacraft first. They told him that the tooling dies used to bend the horizontal ribs were worn and no longer could be used to make them. Antennacraft by the way bought the tooling dies that Finco had when they went bankrupt back in 1984 or 1985. The Antennacraft and Finco parabolic antennas were nearly identical in design. From the pictures posted on your website, the Delhi/Jerrold parabolic appears to be very similar in design to the Antennacraft and Finco antennas also. Channel Master stopped making the 4251 for the same reason. Their tooling dies were worn and could no longer be used to make the horizontal and vertical curved pieces of the parabolic antenna. This happened at the time that Channel Master was close to bankruptcy, so they were not in a position to spend any money to have new tooling dies made. Rich Wertman was told this by CM when he called them to check on remaking the 4251. Rich Wertman then inquired if he could buy the specifications to make the parabolic antennas from the current owners. They looked for the specs, but could not locate them. Apparently someone along the way from their move from NY state to North Carolina or sometime after that, lost or threw out the specifications for the 4251 parabolic reflector. Unfortunately CM had a number of different owners over the years and somewhere along the way they lost the specifications.
Thanks Bob for the superb info!
Possibly, but probably not anytime soon (based on the state of the economy). Bob Seaman also provided this info: Rich Wertman then decided to check a local business that did aluminum fabrication. They attempted to bend aluminum tubing in the parabolic shape they were having difficulty getting it to bend without kinking. Eventually he did locate a business in Utah that told him that they could bend the horizontal and vertical rib pieces for the dish. He just has to get an old 4251 to disassemble and send to them to have them duplicate it. That is where we are now. He has a lead on a couple in his area and I have my eye on a few that are still up on the top of houses in my area. Also there are some out in northwest Ohio or southeastern Michigan that an antenna installer has taken down. We haven't had a chance to get out there yet. If and when the UHF parabolic antenna is remade, the receiving element (folded dipole and the small reflector) will be the one that was used on the Antennacraft 7 FT. model. Rich Wertman spoke to the people at Antennacraft and they said that they could provide that portion of the antenna once the reflector screen portion has been reproduced. Rich did have a tentative cost on it at the time, but with the recent price increases it will now be higher. I believe the original estimate was around $200. I will keep you informed on what develops.
So... if I hear of any more on this I will post it here!
Also, if you cannot wait for a 4251 replacement, there is a source for parabolic UHF antennas but they are expensive. Wade Antenna (http://www.wade-antenna.com/Wade/CATVUHF.htm) does offer Parabolic UHF antennas today, however these are geared towards the commercial market. They are probably too expensive for the average consumer ($1000+) and they require substantially heavy duty mounts.
Because the 4251 has been discontinued, supplies of new ones are depleted (if you happen to find one new in the box consider yourself VERY lucky). If you want performance that is almost as good (note: almost as good, not as good as) the 4251 there is an alternate solution that may be right for you. King Oberlin of KAS Satellite and Cable writes "The hot ticket I've found in anything close to the 4251 in performance has been the Stacked Super-G-1483 UHF antenna collinear package. It has 15db gain with a 30 degree beam width, excellent side rejection but a poor front to back ratio. As long as you don't have a problem with signals interfering 180 degrees behind you, then this package is the hottest UHF array (out of the box) currently available". King has been in the antenna business for 40 years so you can believe that this is a good package. Check out a photo of King doing a Stacked Super-G-1483 installation below:
Update Fall 2011: I installed a Stacked Super G 1483 Antenna on my house (I plan to put the 4251 up one day but wanted something decent in the meantime). This antenna does a lot better than the Channel Master 3671 VHF-UHF Combo antenna that I was using. I receive about 27 channels (including duplicates and subchannels) using this antenna and I am in a very tough reception area. The nice thing about it is that the beamwidth is wide enough that I don't need to rotate the antenna to get the channels I want! The 3671 VHF-UHF Combo antenna could not hold solid reception (on a good day) on some of the channels I wanted. The Super G package holds them all except on the very worst days (heavy snow/fog). I too now recommend this package. I don't have side by side comparision results for it (to the 4251) but it easily outperforms the UHF section on the large 3671 VHF-UHF Combo antenna. To learn more about this 4251 alternate, please check out the Stacked Super G 1483 Antenna page!
This section
contains brochures and technical information regarding the 4251.
Click on the
small images and a large format image will open in a new window!
Channel Master UHF Antenna Brochure This is the front page of a 4 page Channel Master brochure covering their line of UHF antennas. This is from around 1986 (when I bought my 4251).
Channel Master 4251 Catalog Page Here's the page from the Channel Master catalog that shows the 4251 (and its smaller brother the 4250). This catalog is from 1986. Notes that appear in the margin were written by me.
Data Sheet for Stacking Two 4251 Parabolics Direct from Channel Master, here's how to stack a pair of 4251s vertically!
Data Sheet for Stacking Four 4251 Parabolics This array would be the ultimate DREAM of all DXers and serious TV enthusiasts! One 4251 is a formidable antenna, imagine the power of FOUR of these units working in tandem! The rotor needed for this array would need to be massive (as would the mast members). I doubt anyone could find 4 new 4251s to stack like this today. The fact that Channel Master had this information indicates that someone somewhere had an array like this at one time!
In regards to my last comment above, Frank from Macomb IL writes " I remember it well. It was BOB COOPER, back around 1971, when he lived in Oklahoma City. I don't think that he had it for more than a couple years (not sure if it was lost in a storm or taken down by Bob). As I recall, during the DX opening on or near August 17, 1971, he picked up WSBK-38 (Boston) out there, and in another report he had UHF's from I think Toledo OH or Chicago overloading his system, etc. So, yes, "somebody" did indeed have a quad array of 7-footers in the early days..
That must have been some setup to see!!!
Gain Plot (dBd) for the Channel Master 4251 Parabolic I
got this from Channel Master in 1988. Note that the gain represented on this
chart is the more stringent dB re: tuned dipole (NOT dB re: isotropic). The the
4251 has a bit of a "lull" (having "only" 13+ dB of gain) between about
520-560MHz (roughly channels 22-29). After about 580MHz (Ch 32) the gain stays
at least 16dB and keeps climbing. There are only a few consumer grade antennas
available today that can match the 4251's gain between Ch 22-29 (gain is roughly
13.5 dB in this range). There are no antennas I know of (commercially available
UHF TV antennas) that have the nearly 17 dB of gain that the 4251 has above
around channel 44! The 4251 excels at the highest UHF frequencies. However, the
highest HDTV broadcast frequency will be at Channel 51 once the HDTV transition
is complete, so the 4251's unprecedented gain beyond this channel will be
unfortunately be moot once HDTV is the only broadcast available. By any measure
however, the 4251 will remain one of the best choices for receiving HDTV from
difficult fringe locations (assuming of course you have one or can get one). If
you cannot get a 4251 and you want this kind of performance for off the air
reception, you have two options: (a) stack 2 or 4 of the better UHF antennas
available today or (b) spend thousands on a Wade (see link to Wade below) 8 foot
Parabolic antenna (these are aimed at the professional market, not the average
person). 
Beam Width Characteristics for the Channel Master 4251 Parabolic I got this from Channel Master in 1988. Beam width for the 4251 is
quite a bit narrower than many of the Yagi and other UHF antennas available
today (you could match or do better than the 4251 with horizontally stacked
Yagis, but this would be a somewhat complicated installation). Narrow beamwidth
is highly desirable for conditions where multipath is a problem, however the
narrow beamwidth of the 4251 mandates a rotor (otherwise you'll clearly get only
the station you point the antenna directly to). If the 4251 has performance
weakness, it would be its front to back ratio (this is the ability of the
antenna to reject signals coming from the rear). The front to back numbers are
not bad, however a Yagi (one that is large enough to be reasonably competitive
to the 4251 in terms of gain) will have a better front to back ratio as compared
to the 4251. The reason the 4251's front to back ratio is not its strong point
is the spacing of the reflector radials on the parabolic screen. Smaller spacing
would improve the front to back ratio very much, however the problem of wind and
especially ice loading would mean that the antenna would be much more
susceptible to storm damage (not to mention the rotor and mounting masts would
need to be all that much stronger too). The design is a compromise between
performance and durability. If you have ever seen the older satellite TV dishes
(the big ones from the 70s and 80s) you may have noticed that the screens have
very small holes in them. You have almost certainly noted that the satellite TV
dishes of today (Dish Network, etc) are solid. The reason for this is that as
the frequency becomes higher, the parabolic reflector must be made of radials
that are spaced closer together in order for the signal to see the reflector as
"solid". If the spacing is too wide, the signal will pass through it! At UHF
frequencies a spacing of an inch or so would be ideal, however as described
above this would make a UHF antenna very difficult to design to withstand the
weather it would typically see. 
Channel Master 4251 Parabolic Antenna Assembly Instructions (Sheet 1) The original instructions from my 4251. If you are lucky enough to find a 4251 to restore these may be of use.
Channel Master 4251 Parabolic Antenna Assembly Instructions (Sheet 2) The original instructions from my 4251.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
4251 Feed Photo Photo provides dimensions of the 4251 feed in case you need to repair or fabricate one.
This section contains
photos of the 4251 and related items.
Click on the small images and a large
format image will open in a new window!
4251 at Norwich CT Here is my first installation for the 4251. I lived in one part of a 3 family house. Access to the roof was incredibly simple... go up some attic stairs, into the lookout tower, open a window and climb out. The roof pitch was very shallow (you could sleep up there with little risk of rolling off at night). This made working on the 4251 very easy. The downside of this site was that this house was in a deep narrow valley. Most of the stations were to the west, and pointing west the antenna was looking into a cliff of solid rock!!!
4251 at Norwich CT Another view of the Norwich CT 4251 installation. I did not have a preamp on the antenna at this time.
Snow Covered 4251! An early (and heavy, wet snow) fell in November 1986. The 4251 was pretty well coated with snow (this shot obviously taken at night with a flash). As access to the roof was so easy here I shook some of the excess snow off the antenna after taking the picture.
4251 Box I know this picture makes it look like I lived in a "dump", but the old refrigerator gives some scale here. The 4251 box goes almost to the ceiling! I had this box strapped to a Chevy Cavalier on the 4251's ride to its new home!.
4251 in the Attic I had to move out of the 3 family house and the new placed I lived in
did not allow outdoor antennas. So, I hooked it up in the 
4251 at Oakdale, CT Here's my first installation of the 4251 at my new place in Oakdale, CT during the fall of 1988. The physical installation left a bit to be desired (it was later heavily fortified). Reception at this location was excellent to the south, west and north. East was blocked fairly well by a hill. Note in this installation I have added a rotor bearing. This accessory greatly minimizes torque and stress on the rotor. Also I now have a Channel Master preamp on the 4251. In the foreground is my smaller VHF-FM-UHF combo antenna and below that is a 10 element FM Yagi from Radio Shack (actually manufactured by AntennaCraft).
4251 at Oakdale, CT A more distant shot of the 4251 antenna shows how high up I had it. No one ever complained to me about the looks (a few neighbors were more "curious" about what it was for).
4251 at Oakdale, CT Another shot of the antenna farm at Oakdale CT. This photo shows the new VHF-FM-UHF combo antenna I installed (it replaced the smaller one shown before). This was a great all-around antenna but the UHF section was "no match" for the 4251.
4251 at Oakdale, CT This shot shows my later installation (after 1993 when I put a new roof on). The guy wire anchors are now incredibly strong (steel plates with large eye bolts secured to the 2x6 beams for the roof). I had the mast rigged on a hinge type base. This made it fairly easy to lower the mast down for experiments, upgrades, etc. I would turn the antenna to the proper direction, release some of the guy wires, and then lower it down so that it was lying on the roof. This allowed me (alone) to service the unit without any assistance.
My 4251 at Oakdale, CT A shot with a higher quality camera.
My 4251 at Oakdale, CT Another high quality shot using a mild telephoto lens. Note the Channel Master preamp mounted on the antenna. My 4261 was about 8 years old when this was taken!
Night shot of my 4251 at Oakdale, CT This shot was taken really more for my interest in astronomy. You can see the 4251 on my roof clearly in this roughly one half hour time exposure.
Robert Eder's 4251/3617B "Dream" outfit Robert Eder of Iowa has what many would consider to be a dream setup. A Channel Master 4251 Parabolic UHF and a Channel Master 3617B VHF antenna on a tower! The 3617B is the largest all channel VHF antenna made by Channel Master. Robert reports getting HD reception from stations over 90 miles away with this rig. Below a list of the gear in Robert's installation:
(Photo by Robert Eder)
Tony Mantovani's 4251 Installation A side view of the 4251 (note additional antennas in the background). (Photo by Tony Mantovani).
Tony Mantovani's 4251 Installation Front view of Tony's 4251. (Photo by Tony Mantovani).
Richard Gray's 4251/3671 Installation Richard got this 4251 for $50 from someone who e-mailed me saying they had one up for sale. The antenna was purchased a bit before hurricane Gustav hit the gulf coast area. Richard writes "It's [the 4251] already reached out over 70 miles and weather conditions were not that great (band was really dead)!
" Richard also writes "And yes, that is a flamingo on top....... Long story". (Photo by Richard Gray).
A 4251 at Sunset A unique shot of a 4251 installation at Mariposa CA. (Photo by Keith ______).
John Sherman's antenna farm with SIX phased 4251 Parabolics! Check out this setup! John Sherman has SIX 4251 Parabolics phased to one downlead!!! Also in this photo are 4 Channel Master 1110 antennas (phased), along with what looks like a Channel Master Diamond Quantum 4257, also a 4248 (UHF Yagis). Also I see what look like 2 stacked VHF low band (maybe channel 3 or 4?) antennas (the large ones at left). In addition I see two other antennas that look like VHF-Hi band antennas (maybe channel 12 or 13). THis is not all John has! See some additional photos below!
John Sherman's antenna farm with SIX phased 4251 Parabolics! Another view of John Sherman's vast antenna farm.
John Sherman's antenna farm (at his house)! John Sherman's business has a virtual (and powerful) forest of antennas at his business (above). This photos shows what he has on his house! Note of course there is a Channel Master 4251 along with several other antennas. I see what looks like a CB 4 element (dual polarized) beam, several scanner band antennas, and several other antennas that look to be HAM band units. John Sherman's house looks a lot like my antenna doodle (see photo in section below) from back when I was a kid. John HAS what I wanted as a kid!
John Sherman's antenna farm (at his house)! Another view of John Sherman's roof at home.
A 4251 Rescue! A gentleman wrote to me and provided this photo of a used 4251 that he obtained from another person who no longer used it. It looks to be in great shape!
4251 Disassembled A photo of a disassembled 4251. Note that it fits nicely into a small pickup truck. The 4251 comes apart pretty easily after removal of 3 or 4 bolts and wing nuts.
Robert Witzke's newly installed 4251 Robert from Michigan writes "This is Mr. King Oberlin of KAS Satellite and Cable installing my new Channel Master 4251 antenna. He had two (2) left in stock, and I got the LAST ONE he had in stock. New in box never opened." Photo by Robert Witzke.
Robert Witzke's newly installed 4251 Another shot of Robert's 4251 being installed. Photo by Robert Witzke.
Robert Witzke's newly installed 4251 This is a view of the Channel Master 4251 antenna looking from the Right Front corner of Robert's house. Photo by Robert Witzke.
Robert Witzke's newly installed 4251 This is Robert's Channel Master 4251 UHF antenna on top with the Antennacraft B57G VHF antenna below (along with a Spartan 3 antenna amplifier, mounted on a 5' tripod). Robert note that this installation provides "BEAUTIFUL" reception. Photo by Robert Witzke.
Robert Witzke's newly installed 4251 This is a close-up view of the Channel Master 4251 antenna with the Antennacraft B57G antenna mounted below. Robert writes "I wanted to mention that Mr. King Oberlin of KAS Satellite & Cable installed my new
Channel Master 4251 antenna system on Tuesday March 31, 2009. Got the LAST ONE from him. A PERFECT job, and a PERFECT installation." Photo by Robert Witzke.
Glenn's 4251 Installation Glenn (who grew up in Ware MA) writes "I received tv in the 70's from Hartford, Springfield, Providence and Boston. Many towns from Worcester to Springfield had parabolics". Ware was pretty much in the fringe area for UHF for all those towns, but with a decent location and an antenna like the 4251 one could pull in a BIG variety of stations (especially back in the days when there were independent stations on the air). Here's a shot of Glenn's installation as it looks today (the 4251 was installed in 2000). Photo by Glenn _______.
Glenn's 4251 Installation Another shot of Glenn's 4251 installation. Glenn writes "This shot was in '07. It was taken down Labor Day for a new roof that week. It was secured in the attic with long bolts through 2x4's across the rafters. I have a brand new 4251 in the box,but I don't want to drill 3 holes in my new roof. I have already talked with people I know about a small tower. I miss it and all the talk about that "THING" on my roof.
"
Glenn's 4251 Installation Another angle on Glenn's 4251 installation. Note all the other antennas! I see a UHF/VHF Channel Master Quantum (lower left), what looks to be a conical yagi, a UHF multi-bay bow tie antenna (above the conical yagi) and two smaller (possibly VHF or FM) antennas that appear to be stacked (lower right). Photo by Glenn _______.
Richard Gray's VIP307 and 4251 Installation Richard writes "Here are the new pictures of the 4251 with a Wade VIP-307 hung underneath . The Channel Master has been moved to its own rotor on the back of the house. Everything in the yard is in disarray because a large Ceder tree decided to come down on the back of the house. If the CM3671 had been where it is now it would have been damaged pretty bad.
The CM4251 is used for daily 100 mile away digital viewing. I routinely aim it west as Austin Texas comes in once and a while. Houston is a bit more reliable. " Photo by Richard Gray.
Richard Gray's VIP307 and 4251 Installation Richard writes "The VIP-307 has Mexico on right now. It looks like Matamoros on low band VHF". Photo by Richard Gray.
A Home Made 4251!!! Check out Albert O'Brien's home built 4251! Albert writes "Here is a shot of my home made copy of a Channel Master 4251. It is not an exact copy of the 4251 but it has the 7 foot dish and double bow tie elements. I built it over the winter in my shop. How does it work? Very well... I live near Youngstown Ohio and can watch WIVB Ch4 in Buffalo NY almost 150 miles away. I also can get CTV in Canada". Note the reinforced joints on the frame (and also the middle rail at the back of the frame, not present on a commercial 4251). (Albert must have one very good shop!) Photo by Albert O'Brien.
Ed Locker's 4251 installation. This is a very solid install. Note the antenna mast has tremendous support (in that it is enclosed within the tower). Ed is using a CDE rotor and a Winegard PA 4975 driving RG-11 coax. Ed writes "Lots of gain and is it ever tight!" Photo by Ed Locker.
Ken's 4251 Ken writes: I installed a 4251 around 1977 to help with my TV-DX hobby. My best catch using it was a Nebraska UHF station (somewhere around channel 43, I think) from my home here near Dayton, Ohio. Quite an amazing antenna. I've attached a photo of my 4251, taken in early 1977. I went away to college in the fall of 1977 and got away from TV-DX'ing. I eventually took the antenna down and gave it to a friend - the same one that told me about your site. As far as I know, he still has it in storage somewhere today. As I recall, one of the largest horizontal elements near the center fractured and broke at a bolt hole where a vertical rib attached, but other than that it was in pretty good shape.
[added May 2017]
Click on the small images and a large
format image will open in a new window!
Below is some information I was able to locate on some of
the other competing parabolic UHF antennas that were available at one time.
Lafayette Parabolic UHF Antennas Here's a portion of the 1969 Lafayette Radio catalog that features their two UHF models. Look at those prices! Of course, $26.50 was quite a bit of $$ back then...
Antennacraft Parabolic UHF Antennas Here are
AntennaCraft's entries for the UHF Parabolic market. These look very much like
the ones 
Delhi/Jerrold Parabolic UHF Antenna Here is the UHF Parabolic contender from Delhi/Jerrold (along with some of their other UHF antennas). It looks very similar to the AntennaCraft and Lafayette units. This is from a 1986 catalog.
Channel Master 4251 with 20 Ribs Steven Melby sent me this, apparently in 1965 the 4251 had 20 ribs (a good number more than the later version). My guess is that the closer ribs were vulnerable to snow and ice load, and this is possibly why the change was made.
None currently available
From time to time I get leads on parabolic UHF antennas (new and used) for sale. If any are currently available they are listed below. I do not get a "cut" of any financial dealings with these antennas, this listing is strictly to help out fellow antenna enthusiasts. Please be aware that any and all deals worked out are strictly between the party selling the antenna and the party buying the antenna.
Here are some photos and drawings of other antennas that you may find interesting (if you are an antenna nut like I am)!:
Radio Shack U-100 UHF Antenna This is the UHF antenna I used prior to the 4251. This is probably an AntennaCraft antenna (sold by Radio Shack). This was a decent antenna... however the 4251 basically runs circles around it.
Radio Shack U-100 UHF Antenna at Night Here's a unique shot of the U-100 with a starlit background sky. The stars are out of focus (it is not practical to have both the antenna (8 feet away) and the stars (basically at infinity) in focus at the same time.
Antennas at Oakdale Here's a new (at the time) VHF-FM-UHF combo antenna I installed (it replaced the smaller one I had before). Below that is a Radio Shack 10 element FM antenna (actually an Antennacraft FM-10).
Winegard TV Antenna This is the TV antenna setup we had on our house from around 1965 until the mid 1980s. We were at a reasonbly good altitude (550 above sea level) and had a decent shot to Boston, and this modest VHF antenna could pick up Boston pretty well on most days. The UHF only antenna at top could not pull the Boston UHF (70 miles away), but it could pull Worcestor MA.
AntennaCraft FM-10 These were sold by Radio Shack under the Archer name. I had two of them. This is my "low" mounted beam. I mounted it under a CB antenna (for lack of anywhere else to put it). Note that I had it on a rotor however the CB antenna did NOT rotate with the FM antenna! Basically I "reverse mounted" the rotor on the mast. This worked well, however when rotating the rotor I had to remember that "east was west" and vice-versa.
AntennaCraft FM-10 October 1978 photo. Here is my FM-10 and below it is my FM Omnidirectional antenna. I did a lot of FM DXing back in the late 1970s using this antenna rig!
Super-Mag CB Antenna December 1977 photo. This was my father's CB antenna, it was on the house since around 1965, then I took it over in 1977 when I got my CB for Christmas. Lots of fun conversations went out over this antenna!
Radio Shack .64 Wave CB Antenna 30 June 1978 photo. This CB antenna was my high school graduation gift (I still have it but it is not mounted at this time). This antenna replaced the old Super-Mag (its SWR was getting a bit high). The .64 wave was an excellent performer. I remember talking some very good distances with no skip involved!
Antenna Doodle 4 June 1978 sketch. Here is an old sketch I did while in High School (it's a wonder I graduated with all the daydreaming I did about antennas)! Clearly I was an antenna nut from a young age. From this doodle you can tell what I wanted: the best of everything. A large "Moonraker" CB beam on a tower, a large FM antenna, a parabolic UHF antenna, a large VHF TV antenna, and a scanner omni antenna. Although cool looking a house with all these antennas mounted as shown would not be practical (they'd all be interfering with each other). I was probably one kid in a thousand in high school daydreaming about antennas... most guys were looking at the girls (well I did that too of course)!
Antenna Doodle 2 1977 drawing. Here's another early antenna doodle (drawn while I was supposed to be paying attention in class in school)! This photo shows an unwise arrangement of antennas on the right end of the house (that much mast on a small rotor would spell disaster sooner or later)!
Antenna Doodle 3 1979 drawing. Here are my plans for stacking two AntennaCraft FM-10 antennas. At right are the prices of all the components needed (in 1979 prices)! To the bottom left is my work schedule (I worked rotating shifts at a chemical factory at the time). I did eventually stack the two antennas but its performance was really no better than one antenna alone (I think I know why now however).
Robert Eder's Parabolic Antenna Farm Robert Eder sent me this photo of his Satellite dish farm. Equipment includes: Raydx 10.5' Chaparral Dual C Feedhorn DSR-920; Raydx 8' Chaparral Corotor II DSR-920; Unimesh 7.5' Chaparral Corotor II DSR-920; and a
Channel Master 7.5' DSR-920.
Channel Master 3671 VHF-UHF Combo antenna Here's a shot of my recently installed Channel Master 3671. At this time this appears to be the best all channel TV antenna available from Channel Master. A number of years ago they offered the VHF only Crossfire 3617B, this was among the largest and most capable all channel VHF TV antennas ever made (See Robert Eder's 3617B in a photo above). Construction quality of the 3671 is excellent. Its UHF section is no match for the 4251 Parabolic, but for many applications it is all one would require. VHF gain is around 10 dB in the hi band (similar to single channel 10 element antennas) and around 5 to 6 dB in the VHF low band. Mounted below the 3671 is an FM omnidirectional antenna.
John Sherman's Channel Master Quantum 1110 Antenna John Sherman (who has a VAST antenna setup, see the section above) also has a CM 1110 antenna on his house. This antenna (now discontinued) was known for incredibly high front to back ratio (around 35 dB) and also superb side rejection. This was the largest VHF only Qunatum antenna that Channel Master offered. The other one they made was the Crossfire 3617B, see a photo of this antenna above (Robert Eder has one).
John Sherman's Channel Master Quantum 1110 Antenna Another view of John Sherman's CM 1110.
Tim Alderman's UHF fed Dish Tim Alderman sent me this photo. Tim modified a satelite dish to work with UHF. Basically he mounted a 4251 feed to a 10 foot dish! This antenna would basically have about 3 dB more gain as compared to a standard 4251 (along with a better front to back ratio). Tim has articles here: http://electron.org/articles/ .
Richard Gray's Finco 400-A Some people may remember the old Finco 400-A antennas, they had the nickname "bed spring". Richard Gray built one! Richard writes "Finally got time to get the monster finished. It is eight feet across and seven and a half feet high. It is huge! Its reception is remarkable! It has the best VHF I have ever seen and its UHF is equal the my CM4251! It's extremely directional and as the old Finco ads said, 150 miles! It does that with ease!
". Very cool project Richard! Note: you can also see Richard's 4251 in the background.
Finco Bedspring Antenna My apologies on this one... I lost the text that goes with it. A visitor sent me this last summer and due to various reasons I only got to post it in January 2011. If you are the person who submitted this image can you resend me the description that goes with it?
Mike's Antenna Mike writes: I am a TV DXer near Lebanon, IN, and enjoy working with and testing various antennas. Back in 2009 I also put a UHF feed (4220HD) on an old 10' C band dish. In 2013 I rescreened it with 1" chicken wire and put it on my crankup tower. Above it is my Antennacraft CS-1100 VHF antenna. [added May 2017]
Mike's Antenna Mike writes: I am a TV DXer near Lebanon, IN, and enjoy working with and testing various antennas. Back in 2009 I also put a UHF feed (4220HD) on an old 10' C band dish. In 2013 I rescreened it with 1" chicken wire and put it on my crankup tower. Above it is my Antennacraft CS-1100 VHF antenna. [added May 2017]
Rare Parabolic David writes: Been looking for a 4251 for some time and stumbled upon a interesting parabolic today in a barn. It folds in half like a clamshell and is 7 feet inside from end to end when fully open. 3 feet wide. No markings that i can find. Ever see one of these? Great condition overall. I am a little hesitant to put it outside since these style antennas are rare - Might become my attic mount. [I have seen them on occasion but not sure who made them]
[added May 2017]
Below are some links that antenna fans may find interesting:
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