iView-3500STB Tuner & DVR Owners Thread - Page 122 - AVS Forum
Forum Jump: 
 24Likes
Reply
 
Thread Tools
post #3631 of 3660 Old 09-11-2014, 03:13 PM
Member
 
Join Date: Sep 2014
Posts: 21
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 0
Quote:
Originally Posted by DeathStalker57 View Post
Ok so I tired the v1 firmware with no success still no cable channels only over the air channels. I so I upgraded it to v3 and still no channels. It is set to cable scan and I'm in the USA. I'm not using an antenna because I'm just trying to use the dorm room 75 ohm cable jack and get some channels since my TV is effectively a monitor.
Did you try to scan all channels? When I first setup my iView it scanned both OTA and cable as part of the installation process, I didn't set the scan for Air or cable. Just a thought.
AntheaH is offline  
Sponsored Links
Advertisement
 
post #3632 of 3660 Old 09-11-2014, 03:15 PM
Member
 
DeathStalker57's Avatar
 
Join Date: Sep 2013
Posts: 45
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 11
How do I scan all channels? Can I do them both at the same time? I live in a fairly new place so I don't know why it won't work
DeathStalker57 is offline  
post #3633 of 3660 Old 09-11-2014, 03:16 PM
Member
 
DeathStalker57's Avatar
 
Join Date: Sep 2013
Posts: 45
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 11
I see there is a manual scan option but I don't know how to set that and what to look for since I'm in Syracuse NY
DeathStalker57 is offline  
post #3634 of 3660 Old 09-11-2014, 03:21 PM
Member
 
DeathStalker57's Avatar
 
Join Date: Sep 2013
Posts: 45
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 11
I don't know any of this technical stuff about frequency's for manual search or what to do. All I know is I have it plugged in right
Attached Thumbnails
Click image for larger version

Name:	1410473991122_1410474027759.jpg
Views:	19
Size:	148.1 KB
ID:	258306  
DeathStalker57 is offline  
post #3635 of 3660 Old 09-11-2014, 03:23 PM
Member
 
DeathStalker57's Avatar
 
Join Date: Sep 2013
Posts: 45
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 11
Quote:
Originally Posted by AntheaH View Post
Quote:
Originally Posted by DeathStalker57 View Post
Ok so I tired the v1 firmware with no success still no cable channels only over the air channels. I so I upgraded it to v3 and still no channels. It is set to cable scan and I'm in the USA. I'm not using an antenna because I'm just trying to use the dorm room 75 ohm cable jack and get some channels since my TV is effectively a monitor.
Did you try to scan all channels? When I first setup my iView it scanned both OTA and cable as part of the installation process, I didn't set the scan for Air or cable. Just a thought.
When I do a over the air channel scan I get no results (probably since I don't have an antenna)
DeathStalker57 is offline  
post #3636 of 3660 Old 09-11-2014, 03:39 PM
Member
 
Join Date: Sep 2014
Posts: 21
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 0
Quote:
Originally Posted by DeathStalker57 View Post
How do I scan all channels? Can I do them both at the same time? I live in a fairly new place so I don't know why it won't work
I don't have my manual with me, but if memory serves me, you choose MENU then tab along until you find the tab with the scanning option. The first option, before the Manual scan option, is what you want to choose.

Do you have the cable connected to the antenna IN connection on the iView? How do you have the iView connected to your TV/Monitor?
AntheaH is offline  
post #3637 of 3660 Old 09-11-2014, 03:41 PM
Member
 
DeathStalker57's Avatar
 
Join Date: Sep 2013
Posts: 45
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 11
Quote:
Originally Posted by AntheaH View Post
Quote:
Originally Posted by DeathStalker57 View Post
How do I scan all channels? Can I do them both at the same time? I live in a fairly new place so I don't know why it won't work
I don't have my manual with me, but if memory serves me, you choose MENU then tab along until you find the tab with the scanning option. The first option, before the Manual scan option, is what you want to choose.

Do you have the cable connected to the antenna IN connection on the iView?
Ok so once I'm in the manual scab option what settings do I choose? Quite a few which I don't understand
DeathStalker57 is offline  
post #3638 of 3660 Old 09-11-2014, 03:41 PM
Member
 
Join Date: Sep 2014
Posts: 21
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 0
This is the manual link, btw

http://www.iviewus.com/download/manu...0stbmanual.pdf

The top of Pg 10 has the instructions under "Channel Search Options".
AntheaH is offline  
post #3639 of 3660 Old 09-11-2014, 03:42 PM
Member
 
Join Date: Sep 2014
Posts: 21
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 0
Quote:
Originally Posted by DeathStalker57 View Post
Ok so once I'm in the manual scab option what settings do I choose? Quite a few which I don't understand
press the SCAN button on the remote control or use the AUTO option
AntheaH is offline  
post #3640 of 3660 Old 09-11-2014, 03:46 PM
Member
 
DeathStalker57's Avatar
 
Join Date: Sep 2013
Posts: 45
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 11
Quote:
Originally Posted by AntheaH View Post
Quote:
Originally Posted by DeathStalker57 View Post
Ok so once I'm in the manual scab option what settings do I choose? Quite a few which I don't understand
press the SCAN button on the remote control or use the AUTO option
Ok so as soon as I go into manual settings this pops up is that good? Its an attached image
Attached Thumbnails
Click image for larger version

Name:	1410475489075_1410475502012.jpg
Views:	35
Size:	131.8 KB
ID:	258330  
DeathStalker57 is offline  
post #3641 of 3660 Old 09-11-2014, 03:49 PM
Member
 
Join Date: Sep 2014
Posts: 21
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 0
Quote:
Originally Posted by DeathStalker57 View Post
Ok so as soon as I go into manual settings this pops up is that good? Its an attached image
Yup - now you need to choose the channel you are trying to find so you need to know what the channel number is. tvfool.com should be able to help with that.

It would probably be easier for you to do the Auto Search which should be the option right above manual.
AntheaH is offline  
post #3642 of 3660 Old 09-11-2014, 03:53 PM
Member
 
Join Date: Sep 2014
Posts: 21
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 0
Question

Quote:
Originally Posted by DeathStalker57 View Post
Ok so as soon as I go into manual settings this pops up is that good? Its an attached image
Question - how do you have your Monitor/TV connected to the iView?
AntheaH is offline  
post #3643 of 3660 Old 09-11-2014, 03:54 PM
Member
 
DeathStalker57's Avatar
 
Join Date: Sep 2013
Posts: 45
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Liked: 11
Quote:
Originally Posted by AntheaH View Post
Quote:
Originally Posted by DeathStalker57 View Post
Ok so as soon as I go into manual settings this pops up is that good? Its an attached image
Question - how do you have your Monitor/TV connected to the iView?
Through HDMI
DeathStalker57 is offline  
post #3644 of 3660 Old 09-11-2014, 03:58 PM
Member
 
Join Date: Sep 2014
Posts: 21
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 0
Quote:
Originally Posted by DeathStalker57 View Post
Through HDMI
Ok - I was just wondering if you had set the input on the Monitor/TV so you could see the channels - I'm no expert, just thinking this through with my limited knowledge

I have to switch to either Video 1 or Video 2 or Channel 3 (if using coax). I don't have HDMI on my SDTV so I use the cables or coax to connect.
AntheaH is offline  
post #3645 of 3660 Old 09-11-2014, 05:25 PM
Member
 
maxreactance's Avatar
 
Join Date: Dec 2013
Posts: 27
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 10
Quote:
Originally Posted by JHBrandt View Post
The demod chip did change in the models with the channel 3/4 switch, but it's unlikely that change would affect only VHF. The tuner in the iView and its clones has always been a bit weak, but I can receive all three of your "problem" VHF channels on a Homeworx (iView clone) as far away as Stroud with an attic-mounted Channel Master 4228 antenna and an AntennaCraft 10G212 preamp. So while the tuner may be weak, it is possible to make up for it.

Looking at the tvfool chart you're in a pretty good reception area, but a 36-inch VHF dipole may not be enough. As a quick fix, you could try capacitance hats: crumple a 1-inch-diameter ball of aluminum foil onto each end of the dipole. (Folks have used that trick for ages.)

It should help, but may still not be enough. If not, you could try an antenna with longer VHF elements. Most rabbit ears can easily go out to 42-44 inches each. And if you can get a set with one of those 12-position tuning knobs, you can probably find a setting that improves the signal a bit more.

If that's still not enough, you could mount a small VHF/UHF outdoor antenna in your attic. Many small "outdoor" antennas can even be mounted indoors if you can rig up a stand for them.
Uh, you may be giving bad advice here regarding the length of the VHF rabbit-ear (dipole) elements.

In general, you want to "cut" (size) your dipole elements to a length that is about half the wavelength of the carrier wave you are trying to pick up. This length has the least reactance and gives you the most bang for the buck (longer lengths may have greater reactance and don't really give you that much extra reception in any event).

I haven't looked at your TV Fool link, but you probably are getting your VHF stations on a physical channel that corresponds to the old high-VHF wavelengths (channnels 7-13). If so, the distance between the tips of the rabbit ears should be around 30 inches or so (you can play around with the size to get best reception).

If these are actually UHF physical channels, then you may be out of luck with your loop antenna, they may be out of range. Another thought is true "rabbit ears" are not true TV dipoles unless you can fold them completely flat (if you can, you will get better reception because American TV broadcasting antennas are horizontally polarized, that is, they are "rabbit ears" folded completely flat (horizontal orientation of the antenna).

I personally use either an RCA ANT-751 antenna which was specifically designed for digital television which is rarely broadcast on low VHF frequecies, old analog channels 2-6 (note the size of its VHF elements if you are familiar with the antenna), or more usually and right now, my own homemade antenna consisting of a couple of pieces of clothes hanger wire sized to about 30-32 inches threaded through a piece of sheet metal cut in the shape of hyperbolic double-loop UHF antenna and connecting to the flat-wire leads of an old Radio Shack masthead antenna amplifier. This picks up stations from up to 120 miles away placed in my attic.

--
maxreactance
maxreactance is offline  
post #3646 of 3660 Old 09-11-2014, 06:32 PM
AVS Special Member
 
JHBrandt's Avatar
 
Join Date: Apr 2008
Location: S. Garland, TX
Posts: 1,685
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 70 Post(s)
Liked: 159
Quote:
Originally Posted by AntheaH View Post
I have no clue how I'd go about installing anything in the attic so I'd have to get a professional to take care of that. I thought I'd try the outdoor pole with the satellite dish on it to see if that would improve the reception any on the RCA ANT751 that someone suggested.
Sounds like the attic is your last resort then.

If you can't get good enough reception with an indoor antenna, Terk used to make an antenna that clipped onto a satellite dish. Looked kind of like a bent, folded dipole. It even came with short cables so you could connect it in series with your dish's LNA, and it would send the OTA signals down the satellite cable. At the receiver end you installed a "diplexer" (looked like a splitter) to send the satellite signals to the satellite receiver and the OTA signals to an OTA tuner (the iView, in your case).

I used one of those antennas for several years; even though I'm really too far out in the 'burbs for one, it nonetheless worked fairly well. In your environment it would probably work even better than it did for me.
JHBrandt is offline  
post #3647 of 3660 Old 09-11-2014, 07:07 PM
AVS Special Member
 
JHBrandt's Avatar
 
Join Date: Apr 2008
Location: S. Garland, TX
Posts: 1,685
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 70 Post(s)
Liked: 159
Quote:
Originally Posted by maxreactance View Post
Uh, you may be giving bad advice here regarding the length of the VHF rabbit-ear (dipole) elements.

In general, you want to "cut" (size) your dipole elements to a length that is about half the wavelength of the carrier wave you are trying to pick up. This length has the least reactance and gives you the most bang for the buck (longer lengths may have greater reactance and don't really give you that much extra reception in any event).

I haven't looked at your TV Fool link, but you probably are getting your VHF stations on a physical channel that corresponds to the old high-VHF wavelengths (channnels 7-13). If so, the distance between the tips of the rabbit ears should be around 30 inches or so (you can play around with the size to get best reception).

I personally use either an RCA ANT-751 antenna which was specifically designed for digital television which is rarely broadcast on low VHF frequecies, old analog channels 2-6 (note the size of its VHF elements if you are familiar with the antenna), or more usually and right now, my own homemade antenna consisting of a couple of pieces of clothes hanger wire sized to about 30-32 inches threaded through a piece of sheet metal cut in the shape of hyperbolic double-loop UHF antenna and connecting to the flat-wire leads of an old Radio Shack masthead antenna amplifier. This picks up stations from up to 120 miles away placed in my attic.

--
maxreactance
KJRH/2 is actually on RF 8; KTUL/8 is actually on RF 10, and KOED/11 really is on RF 11. All other Tulsa-area channels are on UHF.

So for VHF, he needs 180-204 MHz. The average wavelength works out to a bit over 1.5 meters. 1/2 wavelength works out to .78 meter or about 31 inches. That's the total length of a half-wave dipole (which is why VHF-Hi+UHF antennas like RCA's ANT751 are so much smaller than the old antennas that were designed for VHF-Lo also).

However, you can get a few dB more gain by treating each half of a pair of rabbit ears as its own dipole. In this case, you want each ear to be somewhat longer than 1/2-wavelength; otherwise the impedance doesn't match where the rabbit ears are connected to the balun (which is usually inside the rabbit-ear housing). Each ear may resonate well, but the signal doesn't make it to the cable. So the "best" length to use is actually a compromise between low reactance and a good impedance match, which is a bit of a black art.

I based my results on the info at http://www.hdtvprimer.com/ANTENNAS/RabbitEars.html. The author of that page actually ran simulation software to determine the ideal length to set rabbit ears for any given VHF channel. In general his results came out a bit longer than 36 inches (except for channel 11); that's why I suggested 42-44 inches.

But if you have one of those 12-position tuner knobs on your antenna, it lets you alter the impedance match, possibly letting you shorten the ears back toward that 31-inch, 1/2 wavelength ideal. It can be finicky though; the OP may just have to find the best combination of rabbit ear length and tuning knob setting by trial and error.

BTW, I agree RCA's ANT751 would probably be a good antenna for the OP's environment.
JHBrandt is offline  
post #3648 of 3660 Old 09-11-2014, 07:36 PM
AVS Special Member
 
JHBrandt's Avatar
 
Join Date: Apr 2008
Location: S. Garland, TX
Posts: 1,685
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 70 Post(s)
Liked: 159
Quote:
Originally Posted by DeathStalker57 View Post
How do I scan all channels? Can I do them both at the same time? I live in a fairly new place so I don't know why it won't work
I wasn't aware you could scan both air and cable at once. In theory, you press Menu, move right to the Channel Search page, press OK, move to the Signal Type, select Cable, then move up to Auto Search and press OK again. With V1 firmware it should find every QAM channel, but encrypted ones won't be watchable. (If you have any of those you'll need to delete them so they won't clutter your channel list.)

If you find absolutely nothing with the signal type set to Cable, try Air. If that works, then you have OTA signals on your cable, not QAM signals. That could mean the cable is hooked up to an antenna, and not your college's cable service.

Another possibility is that some of your cable channels are analog. That's surprisingly common on "in-house" cable systems (college dorms, apartment complexes, etc.) since it lets older, pre-digital TV sets work. The iView cannot receive analog channels.

P.S. For over-the-air channels, you can find the channel numbers you need for Manual Search via a site like tvfool.com. For cable channels, your cable service provider would probably have to provide the channel numbers, and frankly, most of the cable company's customer service reps will probably be completely clueless.
JHBrandt is offline  
post #3649 of 3660 Old 09-12-2014, 07:55 AM
Member
 
Join Date: Sep 2014
Posts: 21
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 0
Quote:
Originally Posted by JHBrandt View Post
Sounds like the attic is your last resort then.

If you can't get good enough reception with an indoor antenna, Terk used to make an antenna that clipped onto a satellite dish. Looked kind of like a bent, folded dipole. It even came with short cables so you could connect it in series with your dish's LNA, and it would send the OTA signals down the satellite cable. At the receiver end you installed a "diplexer" (looked like a splitter) to send the satellite signals to the satellite receiver and the OTA signals to an OTA tuner (the iView, in your case).

I used one of those antennas for several years; even though I'm really too far out in the 'burbs for one, it nonetheless worked fairly well. In your environment it would probably work even better than it did for me.
I don't use the satellite - cut the cord last month and happier without it. No sense in paying for channels that I never use - I watch mainly the BBC shows on PBS. I thought I'd use the pole the satellite was on for the antenna and see how it did before resorting to having an installer put the antenna up on the roof.

BTW, he is a she I'm too smart to be scampering about on roof tops at my age lol
AntheaH is offline  
post #3650 of 3660 Old 09-12-2014, 08:47 AM
AVS Special Member
 
mdavej's Avatar
 
Join Date: Sep 2006
Posts: 9,769
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 308 Post(s)
Liked: 347
Quote:
Originally Posted by AntheaH View Post
I don't use the satellite - cut the cord last month and happier without it. No sense in paying for channels that I never use - I watch mainly the BBC shows on PBS. I thought I'd use the pole the satellite was on for the antenna and see how it did before resorting to having an installer put the antenna up on the roof.

BTW, he is a she I'm too smart to be scampering about on roof tops at my age lol
I used to have the dish mounted Terk myself (it's still sitting in a box in my attic actually - if you want one cheap, PM me). Worked great. Even though your sat dish is out of service, you could still use the old dish for mounting the Terk and the existing wires to get the signal into the house. You could even swing the dish around for the best OTA signal. I couldn't do that when I was running both. I have cable now.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
mdavej is offline  
post #3651 of 3660 Old 09-12-2014, 09:30 AM
AVS Special Member
 
Bismarck440's Avatar
 
Join Date: Dec 2006
Location: NE Ohio... AKA the angry white planet Ohth
Posts: 1,239
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 63 Post(s)
Liked: 17
Quote:
Originally Posted by AntheaH View Post
This is the manual link, btw
Quote:
Originally Posted by AntheaH View Post

http://www.iviewus.com/download/manual/3500stbmanual.pdf

The top of Pg 10 has the instructions under "Channel Search Options".


Was there any manual change for the II?
Bismarck440 is offline  
post #3652 of 3660 Old 09-12-2014, 09:37 AM
AVS Special Member
 
Bismarck440's Avatar
 
Join Date: Dec 2006
Location: NE Ohio... AKA the angry white planet Ohth
Posts: 1,239
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 63 Post(s)
Liked: 17
Quote:
Originally Posted by JHBrandt View Post
Another possibility is that some of your cable channels are analog. That's surprisingly common on "in-house" cable systems (college dorms, apartment complexes, etc.) since it lets older, pre-digital TV sets work. The iView cannot receive analog channels.
The cable operator in my area transmits their 70 channel package entirely in analog, thus no sub channels, poor PQ & erratic aspect ratios... imo they have a lot of nerve charging $74 for the aggrivation. The propoganda they sent out in '09 stated you could no longer get Television without signing up with them.

Unfortunately (at least for my area), TV fool is rather optimistic, I'm 28 miles from my transmitters, where AF sas most stations are 'easy indoor' I find I only get 1 or 2 main channels in with a weak but stable picture. If you live in a dwelling with Aluminum Siding that can also have a negative effect on reception with indoor antennas.

Deathstalker, in many multiunit dwellings I find that the local cable companies have tampered with the wiring so much to make you a captive customer, you may want to look behind your wall plate to see if anything was disconnected.

In my develipment which has a HOA & uses common antennas, the Cable company has bogered the wiring so bad & sliced many connections to the master antennas most of my neighbors have became their captive customers.

Over Memorial Day weekend, my line was either 'cut' or a distribution amp blew, I found the HOA no longer wants to maintain the common Antennas, leaving me to either attach my own or I'll have to splice into my attic setup which feeds the upstairs bedrooms.

Last edited by Bismarck440; 09-12-2014 at 09:48 AM.
Bismarck440 is offline  
post #3653 of 3660 Old 09-12-2014, 11:20 AM
Member
 
Join Date: Aug 2014
Posts: 33
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 0
I put my rooftop antenna in the attic, cheap 15 dollar craigslist buy. Screwed through the pole to a rafter and hooked it to my existing cable with one of those 2 dollar 75 to 300 ohm adapters. Downloaded this app and pointed it where it told me to and I pick up all available channels no problem.

https://play.google.com/store/apps/d...per.free&hl=en
BeatnikV is online now  
post #3654 of 3660 Old 09-12-2014, 12:58 PM
AVS Special Member
 
LenL's Avatar
 
Join Date: Nov 2008
Location: Randolph, NJ, 725' above sea level, 30 miles west of ESB
Posts: 1,477
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked: 108
Iviews

I have 2 original ones for sale. Not being used. Package deal. PM me if interested for details.
LenL is offline  
post #3655 of 3660 Old 09-12-2014, 02:04 PM
AVS Special Member
 
JHBrandt's Avatar
 
Join Date: Apr 2008
Location: S. Garland, TX
Posts: 1,685
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 70 Post(s)
Liked: 159
Quote:
Originally Posted by AntheaH View Post
This is the manual link, btw

http://www.iviewus.com/download/manu...0stbmanual.pdf

The top of Pg 10 has the instructions under "Channel Search Options".
Quote:
Originally Posted by Bismarck440 View Post
Was there any manual change for the II?
The link for the 3500STBII manual is

http://www.iviewus.com/download/manu...TBIImanual.pdf

I doubt there are any significant differences though.
JHBrandt is offline  
post #3656 of 3660 Old 09-12-2014, 02:24 PM
Member
 
Join Date: Sep 2014
Posts: 21
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 0
Question Powered USB Hub & USB Enclosure

Are there any particular recommended:

1. powered USB hubs, and

2. USB enclosures for a HD?

I believe the iView can be a little persnickety about the USB port so I thought I'd purchase a hub to minimize any wear and tear.

Thanks!
AntheaH is offline  
post #3657 of 3660 Old 09-12-2014, 05:22 PM
Member
 
maxreactance's Avatar
 
Join Date: Dec 2013
Posts: 27
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 10
Quote:
Originally Posted by JHBrandt View Post
KJRH/2 is actually on RF 8; KTUL/8 is actually on RF 10, and KOED/11 really is on RF 11. All other Tulsa-area channels are on UHF.

So for VHF, he needs 180-204 MHz. The average wavelength works out to a bit over 1.5 meters. 1/2 wavelength works out to .78 meter or about 31 inches. That's the total length of a half-wave dipole (which is why VHF-Hi+UHF antennas like RCA's ANT751 are so much smaller than the old antennas that were designed for VHF-Lo also).

However, you can get a few dB more gain by treating each half of a pair of rabbit ears as its own dipole. In this case, you want each ear to be somewhat longer than 1/2-wavelength; otherwise the impedance doesn't match where the rabbit ears are connected to the balun (which is usually inside the rabbit-ear housing). Each ear may resonate well, but the signal doesn't make it to the cable. So the "best" length to use is actually a compromise between low reactance and a good impedance match, which is a bit of a black art.

I based my results on the info at http://www.hdtvprimer.com/ANTENNAS/RabbitEars.html. The author of that page actually ran simulation software to determine the ideal length to set rabbit ears for any given VHF channel. In general his results came out a bit longer than 36 inches (except for channel 11); that's why I suggested 42-44 inches.

But if you have one of those 12-position tuner knobs on your antenna, it lets you alter the impedance match, possibly letting you shorten the ears back toward that 31-inch, 1/2 wavelength ideal. It can be finicky though; the OP may just have to find the best combination of rabbit ear length and tuning knob setting by trial and error.

BTW, I agree RCA's ANT751 would probably be a good antenna for the OP's environment.
The best recommendation IS to play around with the size. For a while I used a cheap RCA rabbit ear/loop combo (which may be what the poster is using), still fed through an "unbal" to the presumably 300ohm flat-wire posts on my trusty Radio Shack antenna amplifier. It's been a while, but I do seem to remember having to significantly shorten the rabbit ears to pick up the VHF high digital stations in my area (physical channels 7, 9, 10, 12, 13). With them fully extended, I didn't get those channels, which was quite different than my experience using the same antenna for analog VHF stations, which required full extension to get fairly lousy reception on channel 2, and halfway-decent on the remainder of the VHF dial (3, 4, 5, sometimes 6, 7-11, 13).

So they say there's no such thing as a "digital antenna" but there you go, what worked for analog didn't work for digital, and it was all about the size.

This is why the ANT 751 is a "rational" "digital" antenna for most areas, because they essentially eliminated 3/4 of the size of an old VHF log periodic dipole array, and it probably gets better digital reception (most areas) as a result than the old huge antennas. (Oh, BTW, if you're concerned about a pole, the ANT 751 does contain its own short wall mounted pole, but you may not like that, I certainly didn't, and the mounting gear for the antenna doesn't work well with the pole in my attic, which I don't like, ONE of the reasons I usually use my own homemade antenna.)

As far as impedance matching is concerned, that is another whole black art, but one of the beauties of the half-wavelength dipole is it greatly reduces the reactance of the whole transmission circuit in the first place (which is why it is a "reference antenna"). Actually the EXACT length of the "half-wavelength" varies depending on the thickness and construction of the pole elements, so again, you have to play around with it...

Of course, the single most important thing to play with is direction and location of the antenna; the cheapest antenna you can buy will work quite well located properly (outdoors up high and avoiding trees and other scattering influences generally), which is not of course what the makers of antennas (or even Internet pundits on antenna theory such as myself) would necessarily care to admit. It's not so much how it's designed as where you put it and aim it (well, within reason, but I've definitely found that for digital, HOURS spent finding just the right location and direction of a simple antenna is worth more than spending $hundreds on an antenna that has a higher "distance" rating (which, antenna theory/reality again, probably will get you FEWER DIGITAL stations than the cheap antenna, ANALOG again is actually a different story).

--
maxreactance
maxreactance is offline  
post #3658 of 3660 Old 09-12-2014, 07:34 PM
AVS Special Member
 
JHBrandt's Avatar
 
Join Date: Apr 2008
Location: S. Garland, TX
Posts: 1,685
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 70 Post(s)
Liked: 159
Quote:
Originally Posted by AntheaH View Post
Are there any particular recommended:

1. powered USB hubs, and

2. USB enclosures for a HD?

I believe the iView can be a little persnickety about the USB port so I thought I'd purchase a hub to minimize any wear and tear.

Thanks!
How 'bout a powered USB enclosure? I like the NexStar CX, which has both USB and eSATA ports, for the iView and a PC. Mine's a 3.5" model but they make 2.5" models too.

Then you can use a USB-powered hub. I use an IOGear 4-port hub, mostly because it was cheap. Works fine. A hub doesn't draw much current, so it won't overtax your iView.
JHBrandt is offline  
post #3659 of 3660 Old Yesterday, 06:23 PM
Newbie
 
Join Date: Sep 2014
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 0
All I want to do is to record the same show (the news) every week night from an OTA antennae. I have reception. I am able to record. I schedule it to record. It records one night, maybe two nights but ultimately the scheduled recording entree is gone and it doesn't record the next night. The scheduled recording disappears from the "schedule" section. I've reprogrammed it 20 times. It's getting frustrating. I have a 3/4 switch. I have firmware v3. This set top box would be perfect if it would just not stop recording the one program I want it to record. I can't find any threads addressing this problem. I feel like this box should be able to do such a basic thing but it won't do it consistently or rather repeatedly and predictably.
cwikkid is offline  
post #3660 of 3660 Old Yesterday, 07:07 PM
Member
 
laridae's Avatar
 
Join Date: Dec 2013
Location: Ontario
Posts: 166
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 22 Post(s)
Liked: 46
Quote:
Originally Posted by cwikkid View Post
All I want to do is to record the same show (the news) every week night from an OTA antennae. I have reception. I am able to record. I schedule it to record. It records one night, maybe two nights but ultimately the scheduled recording entree is gone and it doesn't record the next night. The scheduled recording disappears from the "schedule" section. I've reprogrammed it 20 times. It's getting frustrating. I have a 3/4 switch. I have firmware v3. This set top box would be perfect if it would just not stop recording the one program I want it to record. I can't find any threads addressing this problem. I feel like this box should be able to do such a basic thing but it won't do it consistently or rather repeatedly and predictably.
I've had timer entries disappear on my Homeworx too but it seems to coincide with only the weaker, intermittent stations.
It records reliably from strong stations, so maybe you can improve your antenna system somehow to improve your chances.

Another possibility is there's a problem with getting the correct time-of-day from some stations since the box doesn't keep it's own time and this will create a problem with the timers. Check the threads for more info on this as it's been discussed at length.

Cable-free since Nov 2013
laridae is online now  
Reply HDTV Recorders

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off