# Bolt's crappy OTA tuners



## Saturn (Apr 10, 2001)

I have been dealing with my Bolt's apparently crappy OTA tuners for a couple years. I'm really close to the antennas for our area (I can see both from my backyard) and I put an overkill UHF antenna outside because it was easy to do and I split the signal 8 ways once it gets into the house, then most of those get split again (e.g. direct to TV, and to a TiVo).

Anyway, after much futzing I got a digiair pro atsc signal meter and it revealed something interesting - if a signal is greater than 0 dBmV, the TiVo will pixelate. Apparently its built-in attenuator can't handle really strong signals. Anyway, I've played with attenuators and selective attenuators and finally ended up just turning the antenna slightly to keep the top two channels at less than 0 dBmV at the TiVo. Great. Except now a 3rd channel (physical channel 11, at -3dBmV) is screwing up, and adding attenuation isn't working.

So maybe this is multi-path, maybe interference, but every other tuner in the house (multiple TVs, and an HDHomeRun) don't have any issues on ANY stations, no matter what direction the antenna is pointed.

I feel like I'm babying this one crappy TiVo tuner and I'm kinda done with it. My family doesn't really use the TiVo anymore and I only use it once a week during football season. I have Plex DVR setup, but it has its own issues, like 30-second skip on a Fire Stick has jittery playback for 0-2 seconds afterward. I don't really want a monthly subscription so Channels DVR is out.

I'm loathe to spend more money on this setup, but are there any TiVos with known-better tuners? I have the TCD849000, are any of the OTA-only TiVos any better?

And yes, I've pulled my TiVo apart to check the ground on the coax is still in place.


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## A J Ricaud (Jun 25, 2002)

Maybe try an LTE filter?


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## Saturn (Apr 10, 2001)

I looked at that, but the station having issues is low frequency (VHF 11 - 201Mhz), and LTE is channels 38-50 (700mhz+).


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## Saturn (Apr 10, 2001)

I ordered a (Philips) LTE filter. I don't have high hopes, but it can't hurt for $10.


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## ClearToLand (Jul 10, 2001)

Saturn said:


> ...after much futzing I got a digiair pro atsc signal meter and it revealed something interesting... ...maybe this is multi-path, maybe interference, but every other tuner in the house (multiple TVs, and an HDHomeRun)...


How does the DigiAir Pro ATSC Signal Meter compare to the HDHomeRun Diagnostics: (*Understanding the signal, strength, and quality readings reported by the HDHomeRun* )?

I currently have a VHF PBS station located ~5 miles away, on a hill, that, using rabbit ears, I can only receive in the winter time (leaves off trees) using a rabbit ear / UHF loop antenna. During the summer it pixelates like mad. Growing up in a borough of NYC (long, long, ago...), neither my immediate family nor any relatives living nearby had need for anything but rabbit ears (most portable b/w tvs of the era had built-in rabbit ears) for NTSC VHF.

Regardless of the signal strength reading on my Roamio OTA (~50-55 IIRC), I couldn't get a stable picture. Once I connected the HDHR3-US I found that only one position of the ~12 position rotary switch on the base of the antenna resulted in 100% *Symbol Quality*. I found that interesting.

From this experience, rather than spend ~$350 for a professional ATSC Signal Meter, I suggest that most folks start with a ~$50 HDHomeRun tuner. As with many other technical 'things', if you can't measure it (i.e. oscilloscope, X-10 Signal Meter, Multimeter, etc...), you can't fix it.


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## Saturn (Apr 10, 2001)

The station having issues on the TiVo shows 94% signal strength, 100% signal quality and 100% symbol quality on my HDHomeRun. But a different station that is reporting slightly stronger in the Digiair pro is showing 90/100/100. A definite lower signal channel is showing 68/100/100, so it seems to be a decent proxy for the signal strength as reported by the Digiair. Which one is more accurate? Hard to tell.


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## ClearToLand (Jul 10, 2001)

Saturn said:


> ...it seems to be a decent proxy for the signal strength as reported by the Digiair. Which one is more accurate? Hard to tell.


IMO, most 'techies' / 'semi-techies' from the NTSC VHF era are accustomed to dealing with just signal strength on some type of meter and actual signal quality by viewing the picture on a tv. Thus, a high signal strength reading for today's ATSC signals is misleading them (temporarily discarding the fact that over 100% usually isn't reported) - per the HDHomeRun LINK I provided above, Signal Quality and Symbol Quality are now part of the equation.

Is it safe to assume that the unlabeled three number groups in your post are values for the HDHomeRun in the order listed in my LINK?


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## Saturn (Apr 10, 2001)

ClearToLand said:


> IMO, most 'techies' / 'semi-techies' from the NTSC VHF era are accustomed to dealing with just signal strength on some type of meter and actual signal quality by viewing the picture on a tv. Thus, a high signal strength reading for today's ATSC signals is misleading them (temporarily discarding the fact that over 100% usually isn't reported) - per the HDHomeRun LINK I provided above, Signal Quality and Symbol Quality are now part of the equation.
> 
> Is it safe to assume that the unlabeled three number groups in your post are values for the HDHomeRun in the order listed in my LINK?


Yes, strength/signal quality/symbol quality, the order in the app and documentation.


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## Saturn (Apr 10, 2001)

Unfortunately, the LTE filter made no difference. I left it on the line (and removed my MoCA filter, as it is redundant) anyway.


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## shwru980r (Jun 22, 2008)

Saturn said:


> I have been dealing with my Bolt's apparently crappy OTA tuners for a couple years. I'm really close to the antennas for our area (I can see both from my backyard) and I put an overkill UHF antenna outside because it was easy to do and I split the signal 8 ways once it gets into the house, then most of those get split again (e.g. direct to TV, and to a TiVo).
> 
> Anyway, after much futzing I got a digiair pro atsc signal meter and it revealed something interesting - if a signal is greater than 0 dBmV, the TiVo will pixelate. Apparently its built-in attenuator can't handle really strong signals. Anyway, I've played with attenuators and selective attenuators and finally ended up just turning the antenna slightly to keep the top two channels at less than 0 dBmV at the TiVo. Great. Except now a 3rd channel (physical channel 11, at -3dBmV) is screwing up, and adding attenuation isn't working.
> 
> ...


I have my antenna mounted to a rotator that is controlled by a control box at my TV. I can move the antenna one degree at a time and check the signal of each channel until I find the perfect antenna position. I think you should try an antenna rotator.


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## Saturn (Apr 10, 2001)

I'm going to try moving the antenna, and maybe building my own. The one I have is very directional which isn't great because the three antennas in the area are all in significantly different directions. The main two are 90 degrees apart from each other and the 3rd is 180 in the other direction entirely. They're all close enough that I can pick them all up no matter what direction the antenna is pointing, but signal strength varies quite a bit when turning it. Also, the antenna is mounted on an old satellite TV mast stuck in the ground on the side of the house. One of the big antennas is straight through my neighbor's house, and our house is aluminum siding. I suspect some of this is messing things up. I'm thinking a DIY bowtie, fractal or omnidirectional loop antenna with no reflector stuck in the middle of the back yard may be better.


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## A J Ricaud (Jun 25, 2002)

Maybe use 2 antennas and one of these?: jointenna tv antenna combiner - Google Search


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## aspexil (Oct 16, 2015)

The thing about any antenna is if you want to improve reception you need to get it as high above ground level as possible. If the neighbors house of aluminum siding is in your line of sight then that will definitely degrade your signal quality. 

If there are any trees in your area you could try tossing a rope over a branch and pull the antenna up that way. I hang many of my amateur radio shortwave dipoles that way. You'll obviously need more coax. 

As mentioned you can join multiple antennas. Most any spiltter will work in reverse as a joiner. You might have to be careful of feedline/coax length on either side so you don't introduce other issues. That is how I have our antennas currently configured in our attic which is 50' above ground level and pretty much pull in 60 stations here in Indy.


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## Saturn (Apr 10, 2001)

I don't have a weak signal though. I have to have a 10dB attenuator an 8-way and a 2-way splitter on the signal just to get the signal below 0dBmV. I may be confusing signal strength with quality, but they are certainly related, no?


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## barnabas1969 (Aug 22, 2013)

If the transmitters are so close, why did you install an outdoor antenna? You are severely over-driving the tuners in all of your devices. If your TV's can handle such a strong signal, kudos to the manufacturers of your TV's!

ATSC signals are amplitude modulated. When the signal is too strong, the demodulator in your tuner cannot detect the differences in amplitude.

When you are that close to the transmitters, A simple, non-amplified, pair of rabbit ears should do.

If you can actually SEE the transmitters from your back yard, you could probably just take a piece of 75 ohm coax and strip off the insulation and the shield, exposing about 13 inches of the center conductor... and THAT will function as an "antenna". Just make sure that the center conductor does not touch any metal objects. Also, make sure that the shield (usually braided wire or metal foil) does not touch the center conductor.

If you make such an "antenna" from a piece of 75 ohm coax (with a male F connector on one end), try to orient the bare copper center conductor perpendicular to the floor (ie. either point it up or down).

You could do this for very little cost. Heck, if you PM your shipping address to me, I'll make it for you. I have plenty of spare 75 ohm coax, and plenty of male F connectors laying around.

Here's a tutorial for creating your own dipole antenna. It's a little more sophisticated than what I proposed above, but it will work well also...

Blue View - Make Your Own TV Antenna - Just a Little Further


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## Saturn (Apr 10, 2001)

So maybe a little background would help. When cutting the cord, I wanted an outdoor antenna for reliability, away from interference of devices in the house, etc. At the time I had 3 TiVos (series 3s) and was using my coax for MoCA too. Between the MoCA, TVs and TiVos, I had 7 or 8 points in the house that needed connections, and some of those points was again split three ways - a TV for direct tuning, a TiVo, and a MoCA adapter. The line comes from outside and goes into an 8-way splitter in the basement (-11dB), and each splitter at the branch locations subtracted 3.5dB, so another 3.5 to 7dB loss. Without taking into account the coax itself, that's 18dB loss. I knew this was non-trivial loss, I really didn't want to get onto the roof, and the two major transmitters in the area were 90 degrees apart, so I got a completely overkill antenna and put it on the previous owner's DirectTV pole in the backyard, put new ends on the existing coax, pointed each half roughly at the antennas, and hooked it into the house's coax, and I was able to draw in every station on every TV and TiVo perfectly. This worked for years, until TiVo basically forced me to replace the Series 3 TiVos with a single Bolt and a few TiVo minis. That's when I started having problems with one particular station. After much futzing I eliminated half of that DB8e essentially turning it into this antenna, and still needed attenuators and noticed the Bolt had issues with any station above 0dBmV (I also noted that it cuts out entirely around -24dBmV). Some more futzing and repointing along with an additional 10dB attenuator on the line and all stations are right below 0dBmV at the same splitter the TiVo is connected to. The previous stations that were having issues for being too strong are no longer having issues, but a different station (measured at -3dBmv) is still having issues.

Yes, it is still an overkill directional antenna, mounted 4' off the ground on a pole rather than the roof or attic, and probably too close to the aluminum siding of our house and maybe blocked by the neighbors for one antenna.

I do have plans to make my own much smaller antenna, something like the OA-432, experiment with mounting options (middle of the yard away from the house, up a tree, on the roof, etc) and see if I can pull in a signal strong enough to still feed the whole house without an amplifier. I'm just waiting for a balun to arrive. I may end up with the thing mounted inside, barely above grade in my basement between the rafters, particularly since we just got snow and then a cold snap..

To complicate things, there is a 3rd antenna with a much weaker signal in a completely different direction from the other two I would also like to pull in, but it isn't one of the major networks so I could do without.


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## barnabas1969 (Aug 22, 2013)

Saturn said:


> So maybe a little background would help. When cutting the cord, I wanted an outdoor antenna for reliability, away from interference of devices in the house, etc. At the time I had 3 TiVos (series 3s) and was using my coax for MoCA too. Between the MoCA, TVs and TiVos, I had 7 or 8 points in the house that needed connections, and some of those points was again split three ways - a TV for direct tuning, a TiVo, and a MoCA adapter. The line comes from outside and goes into an 8-way splitter in the basement (-11dB), and each splitter at the branch locations subtracted 3.5dB, so another 3.5 to 7dB loss. Without taking into account the coax itself, that's 18dB loss. I knew this was non-trivial loss, I really didn't want to get onto the roof, and the two major transmitters in the area were 90 degrees apart, so I got a completely overkill antenna and put it on the previous owner's DirectTV pole in the backyard, put new ends on the existing coax, pointed each half roughly at the antennas, and hooked it into the house's coax, and I was able to draw in every station on every TV and TiVo perfectly. This worked for years, until TiVo basically forced me to replace the Series 3 TiVos with a single Bolt and a few TiVo minis. That's when I started having problems with one particular station. After much futzing I eliminated half of that DB8e essentially turning it into this antenna, and still needed attenuators and noticed the Bolt had issues with any station above 0dBmV (I also noted that it cuts out entirely around -24dBmV). Some more futzing and repointing along with an additional 10dB attenuator on the line and all stations are right below 0dBmV at the same splitter the TiVo is connected to. The previous stations that were having issues for being too strong are no longer having issues, but a different station (measured at -3dBmv) is still having issues.
> 
> Yes, it is still an overkill directional antenna, mounted 4' off the ground on a pole rather than the roof or attic, and probably too close to the aluminum siding of our house and maybe blocked by the neighbors for one antenna.
> 
> ...


You have created your own problem. Have you tried a simple antenna as I suggested in my earlier post?

If you can actually SEE the transmitter towers... you should NOT have an outdoor antenna. Hell, a simple piece of wire stuffed into the F connector on your Bolt should provide more than enough signal for the tuner.

Sometimes, "overkill" creates problems. Use the K.I.S.S. principle whenever possible.

KISS = Keep It Simple, Stupid.

You have created a Rube Goldberg version of your antennae.


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## Saturn (Apr 10, 2001)

barnabas1969 said:


> You have created your own problem. Have you tried a simple antenna as I suggested in my earlier post?
> 
> If you can actually SEE the transmitter towers... you should NOT have an outdoor antenna. Hell, a simple piece of wire stuffed into the male F connector on your Bolt should provide more than enough signal for the tuner.


Yes, I could probably stick a piece of wire into my Bolt and get decent reception on the strongest stations but then the Bolt couldn't connect to MoCA and the TiVo minis couldn't connect to it, Yes, I hook up an external MoCA/Ethernet adapter to the Bolt and solve that problem too. I'm guessing the weaker stations in the area wouldn't work or at least wouldn't work reliably. Then I have two antennas, one directly into the Bolt and another (still outside) for everything else in the house, and the one inside would be subject to people walking around, phones, Wifi, the microwave and whatever else leaks RF.

Tuners have built-in attenuators to handle strong signals just fine, it just seems that the Bolt's is particularly crappy and sensitive to other issues (multipath?) that none of the other tuners I have (Panasonic TVs, a Samsung TV, HD HomeRun, even a crappy Homeworx thing) seem to have trouble with.


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## Saturn (Apr 10, 2001)

And yes, I realize I've overengineered it and caused my own problems here.


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## barnabas1969 (Aug 22, 2013)

Saturn said:


> Yes, I could probably stick a piece of wire into my Bolt and get decent reception on the strongest stations but then the Bolt couldn't connect to MoCA and the TiVo minis couldn't connect to it, Yes, I hook up an external MoCA/Ethernet adapter to the Bolt and solve that problem too. I'm guessing the weaker stations in the area wouldn't work or at least wouldn't work reliably. Then I have two antennas, one directly into the Bolt and another (still outside) for everything else in the house, and the one inside would be subject to people walking around, phones, Wifi, the microwave and whatever else leaks RF.
> 
> Tuners have built-in attenuators to handle strong signals just fine, it just seems that the Bolt's is particularly crappy and sensitive to other issues (multipath?) that none of the other tuners I have (Panasonic TVs, a Samsung TV, HD HomeRun, even a crappy Homeworx thing) seem to have trouble with.


Your WiFi does not transmit on the same frequencies as OTA (Over The Air) TV stations. The frequencies are not even close.

In your situation... because you are close to the transmitters... here is what I recommend:

First, connect a VERY SMALL antenna, such as I described earlier.

Since you want to use MoCA, the output of that antenna should be connected to a POE Filter such as this:
https://www.amazon.com/TiVo-Authorized-Point-Entry-Filter/dp/B01EKCL1U6/

The output of the POE filter should be connected to a SINGLE SPLITTER. It is NOT acceptable for one splitter to feed into another splitter, and so-on. You should NEVER daisy-chain splitters.

If you require more outputs, you should purchase a unity-gain amplifier, like this: https://www.amazon.com/gp/product/B003UH9R2C


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## barnabas1969 (Aug 22, 2013)

Also, if you are a "cord cutter", did you know that DECA products are available?

DECA is equivalent to MoCA. DECA uses a different frequency than MoCA. DECA is intended for use in Satellite TV installations.

If your primary source of "live TV" is "OTA TV", then DECA may be beneficial for you.

DECA equipment is much less expensive than equivalent MoCA equipment.


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## Saturn (Apr 10, 2001)

I'm aware of what frequencies are used for wifi and OTA and that they SHOULDN'T interfere. The same applies to LTE, but they are close enough to cause problems in some situations.

I have a POE filter (recently replaced with an LTE filter, which filters a superset of the POE filter) and a surge protector.

Having one splitter for the whole house would be great, if I had multiple coax runs to each location, but I don't, so splitters must be chained together to support multiple devices on the same line. Yes, I could give up direct tuning on the TVs, but I don't think I should have to.

I've looked at DECA (and even installed a pair of them at a business since they had coax but not CAT5 where they needed data), but it doesn't offer any sort of security and I already have a significant investment in MoCA. MoCA is further away from UHF frequencies than DECA, so I don't really see an advantage there.


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## Saturn (Apr 10, 2001)

Fingers crossed, I may have solved my issues. I made a custom antenna and put it in the backyard rather than the side yard. For now it is mounted on a birdfeeder pole.










I used this site to make a loop tuned for 530Mhz (channel 23) which was one of the weaker ones:
Full Wave Loop Antenna Calculator (22.8 inch loop)

That still left channel 11 (201Mhz) pretty weak, so inspired by the Stealth Hawk design here, I added the dipole, calculated here:
Dipole Calculator (14 inches each side)

I used 12 AWG copper wire pulled from my scrap bin of Romex and hooked it to a balun. And then screwed it to a scrap piece of vinyl plank flooring, and secured it to the pole with a couple pipe clamps.

It only took a little tuning (turning the whole thing a few degrees) to make sure all the channels were coming in equally - this was the most even I've ever seen this graph:









Channel 11 is still a tad bit high (-3dBmV) but the TiVo doesn't seem to care, but it was not happy when 19 was that high - go figure. I originally had my dipole "legs" pointed downward at about a 45 degrees, but despite the digiair saying the signal was good, the TiVo didn't care for it at all and had trouble even displaying a picture. Straightening them out fixed it.

This feeds in where my previous antenna did, though I had to take out the 10dB attenuator. Getting the antenna higher up a tree or on top of the house may get me a cleaner signal, but I don't need it any stronger. I checked all the stations I care about and they appear to be glitch-free, at least for today.

Despite having a nice meter to give actual signal strength numbers, this still all feels a lot like voodoo.


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## mblloyd (Feb 11, 2007)

Saturn said:


> And yes, I realize I've overengineered it and caused my own problems here.


Unless you find that one of the previous suggestions solves your problem, you should also consider that your proximity to the transmitters absolutely requires special attention to prevent strong signals being picked up by your coax shields. A good shield connection at each connector is essential. If you are already using RG 6 coax, you might go to RG 11 and keep the "double shields" separate until you arrive at the destination. Poor connections on the coax can cause packet loses, which result is wield channel responses.


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## Saturn (Apr 10, 2001)

All but one run of my house has RG-6, the one RG-59 is in the basement. Most if not all of the connections have been replaced with PPC EX6 ends. For the cost of upgrading my entire house to RG-11 I could probably purchase a lifetime of subscriptions to all the streaming services.


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## mblloyd (Feb 11, 2007)

Saturn said:


> All but one run of my house has RG-6, the one RG-59 is in the basement. Most if not all of the connections have been replaced with PPC EX6 ends. For the cost of upgrading my entire house to RG-11 I could probably purchase a lifetime of subscriptions to all the streaming services.


Sorry about that. I am sure that double shielded RG-11 is no cheaper now that it was 58 years ago when I was spec-ing it. The connector's price then, out of sight.

I have been having low signal problems and was envious that you could measure your signal strength. Lo and behold, I have learned that my iPad and an app can get the incoming signal strength in dBm from my TCL RoKu TV via its IP address.

NOTE: By various combinations of splitter, no splitter, amp, no amp, etc., on the RG-6 I was able to vary the signal strength by 11 dB. However for any given channel the Tivo showed the same signal strength regardless of combinations, or a straight through. Now I believe what is said about the TiVo signal strength meter. The TCL was spot-on with the amp and splitter dB insertion figures. But showed some variation from one splitter type to another.


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## Saturn (Apr 10, 2001)

So maybe not solved. The first channel that was having problems is having problems again. I now see the that digiair is reporting an SNR of 20-23dB for most stations, which is apparently not great. 

Also, SNR is the same whether connected directly to the antenna or inside the house past all the splitters and coax. So strong signal, just too much noise. When things warm up my antenna is either going up a tree or on the roof.


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## mblloyd (Feb 11, 2007)

I find that my Premier is very touchy about signal strength versus channel (not tuner).. What is good for one channel is either too strong or too weak for another. S/N on all channels is 20-22 dB. I can crank up and down the amp gain from -30dBm down to -49 dBm. Pixilation occurs at either end on one or another channel.
I don’t know if this is normal TiVo performance or not. For instance, I am curious what bad power supply capacitors do in this regard. Or is there a channel frequency versus tuner effect in my TiVo case?
Anyway, I cranked the gain up so a channel had too much signal then I added attenuation (decreased gain) until the channel with pixelation at too much signal was doing ok. I Lucked out; found a setting that worked ok for all 6 channels of interest. I cheated with the antenna rotation so the signal strength was within 2dBm across the channels of interest.
But I don’t understand what I know from this. In a properly operating TiVo there must be a fairly wide range of signal strengths where all channels can work on any of the tuners. Why not in mine?


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## Saturn (Apr 10, 2001)

With just the DB4e I was getting glitching on the one VHF station. With the homemade antenna I was getting glitching on one of the UHF stations. So I've tentatively rigged up this ridiculous setup:

DB4e on the post connected to a 10dB attenuator, going into a splitter, joined with only the dipole portion of the homemade antenna strapped to the birdfeeder to cover the one VHF channel.

It seems to work - I haven't seen any glitching on any stations, but both antennas are still only ~4-5ft off the ground and I'm guessing my aluminum siding is wrecking havoc with certain frequencies, creating nodes, multi-path reflections, etc. I tried the dipole in the same location as the DB4e but it still glitched. I'm thinking this spring I may pick up a real UHF/VHF antenna and mount it above the roofline. I actually just mounted a weather station on a pole above our screened-in-porch. It isn't above our second story but may be a better location? The advantage is that it would still be easier to get to when necessary.

I tried sticking the DB4e in the attic and play around with the signal meter, but it was not showing any better SNR or signal strength than 4' off the ground. And the attic is filled with blown-in fiberglass insulation - an absolutely terrible place to be messing around in.

I also haven't found any correlation between signal strength, SNR, etc. on the Digiair that predicts when the TiVo Bolt would shows glitches. A channel can show -1dBmV with an SNR in the 24dB range and glitch every 10 seconds. Another station may show the same and be fine. A third may show -18dBmV with SNR of 19dB and be perfect.


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