Where to find FM antenna better than the FM6

[skatingrocker17]

Where can I find a better FM antenna than the Antennacraft FM6? I know there are many out there but they all seem to be out of production and I can't find them anywhere. I would even buy a used one.

Centronics appears to have the Winegard 6055p but they're out of business.

I was able to find this (http://www.innovantennas.us/index.php?option=com_virtuemart&view=productdetails&virtuemart_product_id=236&virtuemart_category_id=22&Itemid=167) but it's very expensive. How good of an idea would it be to stack two FM6s?

Thanks.

[No static at all]

Wow, that is a huge antenna. The specs say 6' 7" length, but it sure looks a LOT longer than that. Otherwise, the rest of the specs look great. Never can remember seeing an FM only antenna coming even close to 12 db of gain. And yes, it is a bit pricey (ouch)

You may want to visit the Digital Home site thread on stacking antenna (http://www.digitalhome.ca/forum/showthread.php?t=95148)s to answer questions about stacking. You can generally expect a 2 to 2.5 db increase in gain when stacking 2 identical antennas.

[ADTech]

What do you mean by "better? Sturdier, better construction materials, etc?

What is the specific challenge that you are trying to overcome?

[skatingrocker17]

What do you mean by "better? Sturdier, better construction materials, etc?

What is the specific challenge that you are trying to overcome?

Well I would like one of similar size, not a 12 foot monster with maybe a little more gain. The FM6 is great, but reception of some stations could be better. I'm not looking for sturdier, but maybe more elements than 6 and a little longer. The Winegard 6055P seemed to be perfect but you can't find it anywhere.

How do you connect two antennas? Just connect one terminal to another using a 300 ohm cable? Then from there use a 300-75ohm transformer to coax?

[GroundUrMast]

Here are some links re. stacking/ganging: http://forum.tvfool.com/showthread.php?t=1024

To ADTech's point, are you simply looking for more gain?

[skatingrocker17]

Here are some links re. stacking/ganging: http://forum.tvfool.com/showthread.php?t=1024

To ADTech's point, are you simply looking for more gain?

Yeah, more gain.

Referring to this article (http://www.anarc.org/wtfda/stagger.pdf).... You use a combiner and not a set of twin leads to link the antennas. Is that the best way to go?

[No static at all]

Is there any metal near the FM6 where it is mounted? Have you considered modifying it to improve the pattern?

I have both the FM6 & Winegard 6055 & find the 6055 slightly better, but not by a lot. The modified FM6 is a stellar performer. It see's stations up to 150 miles away (not listenable, but they are heard pretty much 24/7) even inside an attic.

[skatingrocker17]

Is there any metal near the FM6 where it is mounted? Have you considered modifying it to improve the pattern?

I have both the FM6 & Winegard 6055 & find the 6055 slightly better, but not by a lot. The modified FM6 is a stellar performer. It see's stations up to 150 miles away (not listenable, but they are heard pretty much 24/7) even inside an attic.

The mast is metal but I followed the intstructions and made sure there is at least 2" of clearance between the mast and those zig zag things that run down the antenna (forget what they're called). The HD stacker is mounted about 36" below, I'm likely going to take it down when I can find someone to buy it. I can get all the same stations VHF and UHF with the FM6 with the same signal quality.

Are the 2-3dB gains across the whole 88-108Mhz spectrum?

[No static at all]

If stacking 2 identical antennas the average gain increase is ~2 to2.5 db across the entire band.

[No static at all]

I see your HD Stacker is for sale on Ebay. The FM6 is WAY too close to the TV antenna & may be compromising your FM reception.

Once the Stacker is removed, I suggest raising the rotor higher if possible & then put the FM6 5 feet above the rotor. The added height & removal of the Stacker may help clean up 101.5 & other stations you are trying to improve.

[skatingrocker17]

Yeah I'm probably going to take it down today or tomorrow. I have the stacker on Craigslist too but I doubt it'll sell which sucks because I really don't have anywhere to put it.

[skatingrocker17]

I plan on taking the stacker down but I moved it all the way down the mast so there's a good 4 feet separation between the two antennas. Right now seems like a perfect day to see if there's a difference. 101.1 is perfect / slightly staticky at times and after moving the stacker all the way down, it didn't seem to change. Some days all Detroit stations come in 100% clear but today seems to be a bad day. 88.7 is still good though.

I compared tv stations between the two antennas too. All often UHF stations are 100% with the stacker and mostly in the mid 70s to 80s on the FM6, which is to be expected because it's not a UHF antenna. The fm6 gets stations from the opposite direction though so doing a channel scan with the fm6 resulted in 4 more channels. VHF tv is a little better on the stater too but it also has a pre amp and it aimed more for VHF high band.

I bought another FM6, we'll see what that does.

[Pure_RF]

They make an 8, 11, 14, 17 and 18 element FM antenna.

http://www.innovantennas.com/antennas-a-accesories.html?page=shop.product_details&flypage=flypage.tpl&product_id=297&category_id=26

Where can I find a better FM antenna than the Antennacraft FM6? I know there are many out there but they all seem to be out of production and I can't find them anywhere. I would even buy a used one.

[skatingrocker17]

They make an 8, 11, 14, 17 and 18 element FM antenna.

http://www.innovantennas.com/antennas-a-accesories.html?page=shop.product_details&flypage=flypage.tpl&product_id=297&category_id=26

I wonder how well they would work for FM since they're 144Mhz. Anyway, the 10 element one would be over $200 anyway. My 2nd FM6 should be here Saturday morning. I live only about an hour from Solid Signals shipping facility so it always comes next day.

[Pure_RF]

Good on your FM-6. I have a friend using the larger Wineguard and it works well. Where he feels the antenna falls a little short is F/S and F/B performance. But then, its a 6 el antenna on a bit of a short boom. You stack a pair and that should improve plus, you'll pick up around 2.5 db gain.

Ummmmm.... the Inno's linked are not 144 mHz at all. Look at the specs for the 17el, below. Center frequency is 98 mHz. While I think the numbers below have a bit of "blue sky" included and $528.81 USD is a hefty price, with APS being gone, these are high performance alternatives.

Performance:

Gain @ 98MHz :13.26dBi
Max Gain: 13.78dBi
Typical F/B: 28dB
Max F/B: 42.7dB
Gain at 98MHz 10m (33') above ground: 19.01dBi

I wonder how well they would work for FM since they're 144Mhz. Anyway, the 10 element one would be over $200 anyway. My 2nd FM6 should be here Saturday morning. I live only about an hour from Solid Signals shipping facility so it always comes next day.

[skatingrocker17]

You're right, I was looking in the wrong section.
This is the 88-108Mhz section (http://www.innovantennas.com/antennas-a-accesories.html?page=shop.browse&category_id=26).

I really like the 8 element, but it's $200 dollars plus whatever it cost to ship it. It's so strange that almost every good FM antenna is out of production.

[skatingrocker17]

I'm wondering how far apart the antennas should be. The Stagger Stacking (http://www.anarc.org/wtfda/stagger.pdf) has some distances on the last page for stacking. But I'm not sure how the distances would change for vertical stacking.

I might try 3 feet.

[ADTech]

It's so strange that almost every good FM antenna is out of production.

For the same reason that you can't find buggy whips in production anymore - lack of demand.

You should be consulting the reference in post #2, not the stagger stacking reference. There is math that you must do, otherwise you're just wasting time and resources. Also see http://www.kyes.com/antenna/stackluge.html

A correctly done stack will offer up to a 2.5 dB gain AT ONE FREQUENCY only. It will not offer that benefit across the entire band and will most likely have some detrimental effects at frequencies away from the peak.

Typical stacking distance is between 2/3rds and .94 wavelength.

[skatingrocker17]

Okay, so correct me if I'm wrong.

This article (http://www.tvantenna.com/support/tutorials/combining.html) gives the following formula: 467 / (lowest frequency).

So... 467 / 88Mhz = 5.3 feet.

[Stereocraig]

Okay, so correct me if I'm wrong.

This article (http://www.tvantenna.com/support/tutorials/combining.html) gives the following formula: 467 / (lowest frequency).

So... 467 / 88Mhz = 5.3 feet.

That's right for half wave, unless you're talking about each side.
I don't know the exact value, but I've seen it rounded off to 468.

[skatingrocker17]

Here's what it looks like for now...
http://i.imgur.com/CifHvnD.jpg
Hard to tell if it's working any better. I had to cut a longer mast to get the bottom antenna over the peak of the roof. The other one was 60", this one is 100".

[Pure_RF]

Well agreed on all. I had an APS-13 @ 60' until a small tornado took the tower down. While it worked well, unless there were E's or TROPO, the line of sight rule dictated what I would hear. When there was TROPO or E's, my friends Winegard 6055P worked as well.

That's NLA also....

The price of performance FM antennas is certainly up there. If there were a few people who wanted one, a group buy might take the edge off the price a bit. Still....

Thanks for the reply, tho...


You're right, I was looking in the wrong section.
This is the 88-108Mhz section (http://www.innovantennas.com/antennas-a-accesories.html?page=shop.browse&category_id=26).

I really like the 8 element, but it's $200 dollars plus whatever it cost to ship it. It's so strange that almost every good FM antenna is out of production.

[No static at all]

Are both cables from the 2 antennas the exact same length?

Is your FM reception issue mainly static, or are you still experiencing signal fade as well?

Is TV reception affected by the stacked antennas?

[skatingrocker17]

Are both cables from the 2 antennas the exact same length?

Is your FM reception issue mainly static, or are you still experiencing signal fade as well?

Is TV reception affected by the stacked antennas?

I know for sure one is 6 foot, I'm 99% sure the other one is 6 foot as well but I ordered another one that's quad shielded. TV reception does not seem to be affected, radio reception seems about the same, hard to say if it's improved.

[skatingrocker17]

A test I did to compare 1 antenna vs. 2 is tune to channel 11.1 (real channel 11). With two FM6s connected the signal strength was 72%, with one connected (the higher one), the signal strength was 92%.

Is this a good indicator on whether I should use 1 or 2? I know channel 11 is VHF-high whereas FM would be low band.

[GroundUrMast]

A signal from real CH-6 would make a fair test signal, it's at the bottom of the FM band.

Real CH-11 is twice the frequency of the FM band center. It's about as bad a choice as one could hope to find because at 200 MHz, the elements of the FM antenna are twice as long as they should be in order to resonate (that actually forms a type of rejection filter). Your test suggests the combined pair rejects real CH-11 better than a single antenna, possibly due to the filter network formed by the coax + combiner harness + antennas.

For the best shot at a balanced combiner harness, use cables of equal length, cut from the same roll of coax. There can be variations between vendors, so that two store bought cable the same length, but from different sources, may not match well enough.

Quad shielding is not worth paying a penny more for... The point of extra shield is to keep signal from getting into or out of coax that's not directly connected to an antenna. (As in the case of a satellite system where there is a low-noise-block converter between the actual antenna and the coax. In a satellite system the LNB shifts the raw signal from the satellite to a lower range of frequencies. The range used in the LNB to receiver connection overlaps with land based radio services. You need to keep the two from interfering with one another, hence the extra shielding.) In OTA TV & FM, you have an antenna coupled directly to the coax, extra shielding buys you nothing, The antenna is a 'huge leak' in the shielding.

[Pure_RF]

There are 2 critical distances to be calculated. The first, the vertical distance between antennas. Second, the length of the phasing harness (those 2 lengths of Co-Ax which would run from the feed point of each antenna to, in this case, a Co-Ax "Tee" adapter). It's not at all difficult once you know some of the deign parameters. The first, is the physical, vertical separation of the 2 antennas for a specific result from what will be an antenna array.

Just brainstorming here but I'm thinking the physical separation value might be based on the result being a compromise between gain and frequency "broadbandedness." The mfg might already have that value and you might reach out to them and ask. Or, perhaps someone here has modeled an array using those antennas using EzNEC. The second value necessary to calculate the length of the phasing harness is based on the value of the first. That is, what is fraction of a wavelength should the length of the phasing harness be to accommodate the physical spacing value used to achieve the goal of your array.

You will also need the velocity factor of the specific brand of (probably RG-6) co-ax used to make the phasing harness. That probably going to be something like .82, .85 or something like that.

Lets put it all together. I made an 800 Mhz, 4 vertical dipole stacked array. Each vertical dipole needed to be spaced 57" apart to achieve the design goal which was flattening the pattern toward the horizon. I used 3/4 wavelength phasing sections. To determine the electrical length of those cables, I first divided 2952 by the center frequency of the antenna in mhz or, 2952/855 then multiplied that result by the velocity factor of the cable, in my case, .85 which yields the electrical length of my 1/4 wavelength phasing line. However, I needed 3/4 wavelength lines so, I then then multiplied THAT result by 3. THAT yielded the electrical length of my phasing line. So, the formula looks something like this:

2952/855= P (P* .85) = L1 (L1 * 3) = L3

Where P= Physical cable length
L1= Electrical 1/4 wave cable length
L3= Electrical 3/4 wave cable length (desired length)

So, for 98 mHz, 2952/ 98= 30.122"

30.122 * .85= 25.603" or, right at 25 5/8" for each of the 2 harnesses.

Multiply that times 3 and you get a cut length for each leg of your phasing harness of 76 7/8". Remember that an FM Tee is about 3/4 inches long so SUBTRACT HALF that value from EACH of your 2 phasing harnesses.

So, that's what the formula basically looks like. What I am lacking to make it completely accurate to your situation is the mfg's or modeling result to provide recommended spacing between your antennas.

Th example above should not be regarded as a "build to" example in your situation but rather, an example of how do perform the calculations to determine the phasing harness length once you have:

1- The recommended physical vertical antenna spacing in wavelengths for a design frequency. :confused:

2- The velocity factor of the cable you will be using to construct the phasing harnesses. :confused:

Best


Okay, so correct me if I'm wrong.

This article (http://www.tvantenna.com/support/tutorials/combining.html) gives the following formula: 467 / (lowest frequency).

So... 467 / 88Mhz = 5.3 feet.

[Stereocraig]

Your rotor may hold up, but that much mast puts an awful lot of stress, on it.

[GroundUrMast]

Your rotor may hold up, but that much mast puts an awful lot of stress, on it.... And the attachment points where the J-pole bracket and building join.

[Stereocraig]

... And the attachment points where the J-pole bracket and building join.

Yeah, kind of a small footprint.
I guess I was giving somebody the benefit of the doubt, that they hit a truss w/ two bolts.

[skatingrocker17]

Well when I put that up I had a very small antenna and no rotor. It escalated from there. I can't believe it hasn't blown over or fallen off especially because the past few days have been very windy and rainy. I have checked on it, it's still in there just as good as it was the day I put it up which is amazing.

[Stereocraig]

Well when I put that up I had a very small antenna and no rotor. It escalated from there. I can't believe it hasn't blown over or fallen off especially because the past few days have been very windy and rainy. I have checked on it, it's still in there just as good as it was the day I put it up which is amazing.

I only mention it, cause there's no worse feeling, than bent elements, except maybe,for that first dent in a new car.

Any damage to antennas I've ever had, were usually when hoisting it up, or taking it down.

[skatingrocker17]

I'll sure it further when it stops raining.

I'm considering returning the second FM6.

I sold the Stacker but I just realized I have nothing to ship it in. I considered buying the Winegard HD7698P and placing it under the FM6, not directly under but maybe 4 feet down. The antenna is VHF-hi/UHF so I wouldn't think it would interfere. Then maybe I'd have a box to ship the stacker in.

[No static at all]

Excellent, you sold that Stacker faster than expected!!

If you do decide to go with the 7698, keep the mast length 5 feet or less above the rotor. Mount the 7698 no more than 1-2 inches above the rotor to help keep the torque loading to a minimum. The recommended mast length is usually 3 feet or less with light duty consumer grade rotors as they cannot withstand twisting forces like a heavier duty rotor can.

Have you considered a tripod or chimney mount? Not sure if that eave mount will be able to handle the extra load?

[ADTech]

Best of luck when you take that Stacker down to the post office or UPS store to ship it. Be prepared for "oversize" shipping rates.

[skatingrocker17]

I took the Sony X3HD on the roof and performed a direction comparsion with 1 FM6 vs. 2. It didn't seem to have much of an affect on 88.7 CIMX other than RDS was always displayed with 1 FM6 and sometimes with two. 101.1 WRIF was fuzzy with two antennas. So I pointed the lower FM6 at Fort Wayne. 101.1 WRIF was clearer with two antennas (one pointed at Fort Wayne) but still not as clear with just. 88.7 remained consistent, and also added 98.9 WBYR which I liked.

In the end, I ended up taking one FM6 down, it's just better with one. If I ever want to listen to 98.9 out of Fort Wayne I can just rotate my antenna or get in the car.

Excellent, you sold that Stacker faster than expected!!

If you do decide to go with the 7698, keep the mast length 5 feet or less above the rotor. Mount the 7698 no more than 1-2 inches above the rotor to help keep the torque loading to a minimum. The recommended mast length is usually 3 feet or less with light duty consumer grade rotors as they cannot withstand twisting forces like a heavier duty rotor can.

Have you considered a tripod or chimney mount? Not sure if that eave mount will be able to handle the extra load?

I'm thinking the Antennas Direct 91XG (http://www.solidsignal.com/pview.asp?p=91xg&d=antennas-direct-91xg-uhf-tv-antenna-(91xg)&sku=853748001910) or Winegard HD 7698P (http://www.solidsignal.com/pview.asp?p=hd7698p&d=winegard-hd-7698p-high-definition-vhf%2Fuhf-hd769-series-tv-antenna-(hd7698p)). The Antennas Direct has more reviews, not sure which one would be better for UHF. The Antennas Direct is also much shorter.

Best of luck when you take that Stacker down to the post office or UPS store to ship it. Be prepared for "oversize" shipping rates.

Great...