Dallas, TX - HDTV - Page 228

That doesn't mean the amp wasn't working, it usually means the amp wasn't needed in the first place and its installation neither harmed nor helped reception.

If it was faulty, it would have bricked your signals by anywhere from 20 -30 dB causing a loss of your weaker, distant signals. You can test this idea by hooking it up, checking reception, unplugging the power supply without disconnecting anything else, then checking to see if your weaker signals were lost. If so, the amp was working just fine.

If I were installing an amp for the first time into a previously unamplified system, I'd agree with you. But if you check the last several posts, you'll see that's not the case.

You should know I'm dividiing my OTA signal four ways, with about 50' of RG-6 cable from the antenna to any given TV. With no amp, that works out to about 8 dB signal loss (probably a bit more at the top of the UHF band), which would wipe out most of my CM-3020 antenna's gain. In that environment I can receive most full-power stations with some dropouts, but not all, and low-power stations are effectively nonexistent.

I had been using one of the old Channel Master CM-7777 preamps, which cleared up full-power reception and also allowed me to receive all low-power stations in the DFW area. Unfortunately, last month this preamp failed, and I discovered the new version of the CM-7777 was much less suited to my needs (too much gain, way too much noise). So instead, I replaced it with an AntennaCraft preamp with variable gain and a somewhat higher, but still reasonable, noise figure. (Model 10G212 I think)

As I've explained before, the AntennaCraft preamp works reasonably well. However, it's not quite as good as the old CM-7777: a few weak low-power stations no longer come in. So when I learned that Antennas Direct also makes reasonably inexpensive preamps, and that they advertise a better noise figure than even the old CM-7777, I decided to try one (the PA-18) just to see if it'd bring back those weak stations.

Unfortunately, the PA-18 acts as if it's not present at all. I get the same reception as with no preamp. Since the AntennaCraft preamp, in contrast, does significantly improve reception, I can only conclude that my PA-18 doesn't work, or at least, doesn't work well enough to notice.

I admit that I'd expect a non-working preamp to attenuate the signal, as you said. My CM-7777 did attenuate the signal when it failed, and I'm surprised the PA-18 doesn't seem to do that (at least not much; certainly not 20-30 dB). However, as far as I could tell, unplugging the power had no effect.

I did test the power injector. It puts out 15 volts. And since the working 10G212 also uses a power injector, I know the cable will carry power up to the preamp OK.

My best guess is that there's a break within the amp that prevents power from reaching the transistors. It might actually be a simple fix, like a cold solder joint; but the box is sealed so I'll leave more detailed testing to someone else.
Edited by JHBrandt - 2/7/13 at 8:43am

I did a channel add scan tonight and K25FW-D was picked up.

Nothing transmitting, just a black screen, but enough power to register the channel.

My signal strength meter on the Sanyo LCD DP 42840 is not very helpful.

On many channels that I get sound and picture that's watchable, there are no signal strength bars registered.

My test channel is KMPX Ch. 29, where I get three bars.

My next big screen TV will have better OTA features, than that crappy Sanyo, which always defaults to static channel 3, after the TV has been turned off (not unplugged, just powered off.)

I have the same problem with my Media Center and Hauppauge HD PVR 2. KTVT shows as a very week signal rescan does not help. Can usually want CH 11 OK but cannot record. Just started in December.

As I mentioned earlier in this thread regarding KTVT (ch11), I don't understand how it changed reception on the various tuners in my house. When the switch happened, only my tv's seemed to be affected and needed a rescan. My pc tuners kept on going with no problems, even recording several primetime shows on that channel. Strangely, I actually tried to watch the superbowl this past Sunday through my htpc, and it gave me a 'no signal' message! I have no idea how it can record content but not display it. Out of concern that I may now start missing my recordings on that channel, I did a rescan for channels. It did not find any content for 11.1. Then I remembered someone here suggesting the need to 'rescan for additional channels', and it found it then. So all is well.

Funny thing to me, is that this pc has always had data in the guide for 11.1. My other pc that uses my network tuner needed manipulation of the guide data for 11.1. Both pc's run WMC in Windows 7.

I am having the same problem, I was able to restart WMC 7 last Sunday and record the Superbowl. Last night I was making sure it was set to record CSI NY tonight and it worked until I scheduled the recording. Now nothing on 11 or 21.2.

Look up a bit at some earlier posts to see if it explains matters. I lost track of it all! Lol! Try the 'scan for more channels' option in your tv signal setup, see if that helps. It may be convoluted because it appears that different tuners behave differently within WMC. Then there is the issue of guide data, and it's seems to be completely independent of actual channel reception.

Mr Brandt,

Based on the conversation so far, I'd also conclude that the PA18 likely is not defective, it's just not appropriate to your application. My previous offer is still open.



You may get a chuckle out of this one, but I've tested both the old and new versions and the new amp actually better in some ways (but quite different in others) than the old version. It's actually a bit quieter in noise level contrary to the published noise figure which no one previously apparently bothered to actually test. It has a nearly flat 30 dB gain across the entire band with only the optional FM filter. The old version had a notch filter around 300 MHz to filter out interband signals. The old one averaged 4-4.5 dB NF and 22 dB gain on VHF (excluding the FM filter). On UHF, the old one ran from around 2.75 dB NF at 470 MHz to 3.2 dB NF at 700 MHz with gain that ran from 26 dB at 470 MHz down to 24.2 dB at 700 MHz. Single vs dual input for the old one, of course.

I'd say the new one was more of a bollixed marketing job than any deficiency in the hardware.

You would know more about the PA-18's internals than anyone. My 10G212 works best when set slightly above its minimum gain of 20 dB. Anything more and I start to see signs of overload (readings start dropping on weak stations near strong ones, suggesting IM distortion). The PA-18 has somewhat less gain than the 10G212, but I thought ~15 dB would still be plenty. Maybe I could try daisy-chaining a distribution amp after the PA-18. If it's actually working, that'll probably overload; but it might be worth a shot just to see what happens.

This weekend I'm giving the PA-18 to someone who might be able to use it. But if he doesn't want it I'll PM you as promised.

I doubt they changed the basic design (except for eliminating the separate UHF/VHF inputs, which is an issue for some but not for me). My theory is that Channel Master just dialed back their QC, so you may get a good quiet amp or a noisy one, just depending on the specific parts your amp happened to get built with. That's the only reason I can imagine they'd advertise the noise figure with a nonsense phrase like "less than 5 dB;" it could be anything from 2.0 to 4.9; the lower-noise amps are probably more common, but they only reject the ones over 5.0 now.

Yeah, KTVT on WMC is a mess. To summarize, here's what I did that worked on both Win 7 and Win 8:
1. Go through the initial setup; this gives you a KTVT that doesn't work (apparently still looking for RF 11)
2. Do the "Find more channels;" this gives you a second KTVT that works, but has no guide info
3. Go to "Edit Guide," select the KTVT that works and tell it to use the guide for the one that doesn't
4. WMC will give you the choice of keeping both channels or combining them. Choose combine

This worked with an Avermedia Duet tuner card; hope it works for other tuners also

I fixed it! I called KTVT and asked to speak to a tech, I wound up with voicemail so I briefly said what the problem was and fully believed I would never hear back. Later on, I decided to poke around and try a couple of things. I went to settings, guide, edit channels, then clicked Auto Select. Click ok, it then rescanned all the channels and disabled 21.2 which showed to be a CBS affiliate. Like magic, I had channel 11 back! 5 minutes later, a tech returned my call. I told him what I had done and he said there was no 21.2 in the area. No wonder it wouldn't work, the channels were conflicting. When I have a chance, I want to see if I can figure out where the 21.2 came from.

I vaguely recall from some time in the past that a problem on some other station did this before. Perhaps a search here will turn something up. In any case, I did a full rescan on my CM7000 yesterday and it found 21.2 through 21.9. Nothing there of course. I just did it again and they vanished back into the mists from which they came.

There was a channel 21.2 for a very brief period of time in summer 2009. When KTVT was getting reception complaints due to people not receiving its 23 kW RF-11 (VHF) facility, CBS temporarily fired up KTXA's subchannel 21.2 as a simulcast of KTVT as a stopgap measure. The period of time involved was only from mid-June 2009 to early August 2009.

That's well over three years that 21.2 has been gone. Yet Tribune, the operators of zap2it.com still stubbornly keep it listed, playing mayhem with a number of applications using that service for both channel reconciliation and program guide data. I've contacted Tribune both via e-mail and phone to inform them of this continuing error with no response to either method.

The 21.2 through 21.9 your CM-7000 found were probably "echoes" of KWDA's subchannels. The CM-7000 (the converter box, not the Pal DVR) has a habit of occasionally listing RF instead of virtual channel numbers. (I have one and have often experienced this problem myself.) Presumably your final rescan gave you the correct channel numbers of 30.1 through 30.9.

Nope. Other than the case and the model number, there's nothing about the two products that are the same.

Theories may abound, but my examination shows a professionally designed and manufactured amplifier. Anyone who is in a deep fringe location who needs a 30 dB amp with a decent noise figure (better than the old one, in fact) would benefit from this amp. Unfortunately, folks who used the old version successfully may or may not benefit from this one's attributes which are VERY different from its predecessor.

Like I said, a bollixed marketing job... something I can say I've seen before.


Far be it from me to to be the one to point out the features of a competitor's products and the "marketplace's" opinions about it, but I've seen a lot of opinion tossed about with with regards to this amp and not a shred of it was based on any independent technical analysis.

The only caveat I'd like to add is that, unless I miss my guess, you only tested one of the new CM-7777 amps. Of course I've tested zero, so you're way ahead of me. But I must nevertheless caution against drawing broad conclusions from a sample size of one! (Certainly, if you were panning the new CM-7777 based on poor test results from a single amp, Channel Master would be crying foul!)

And I realize this is pure speculation, but I'd bet $10 that if someone tested a dozen new CM-7777's, most would be at least as good as the old ones; but at least one would meet the current advertised spec (< 5 dB) but not the old amp's 2 dB UHF noise spec. I'm not saying this is due to bad design, nor to country of manufacture (my old CM-7777 was made in China and worked great), but merely to variation in parts.

If I'm right, buying the new CM-7777 is a reasonable choice, but a bit risky. Of course if, like me, you don't need 30 dB gain, it may be a poor choice anyway.

Which reminds me: I may have figured out why the PA-18 didn't appear to work.

My 10G212 has a switchable FM trap. Out of curiosity, I switched it off the other day, and signal quality readings dropped a bit - even on UHF. Not a lot, but enough to show the FM trap was keeping the amp from overloading.

Not surprising since I have the 10G212's gain set right on the verge of overload. But if the PA-18 happens to be more susceptible to overload than the 10G212, it could have been overloaded by a nearby FM station, even though it has somewhat less gain than the 10G212. So blocking FM from reaching the amp might have been a simple fix.

Oh one more thing: for anyone who may be thinking "JHBrandt is too stupid to realize he doesn't even need a preamp at all," the return of analog broadcasting provides some contrary evidence. Here's channel 22 without a preamp:


Here it is with the AntennaCraft preamp, gain at about 21 dB:


Still snowy, but the difference is quite clear.

Good to hear the new CM-7777 is reportedly well designed. But CM marketing should definitely state that the noise figure is as low or even lower than the original version. Because replacing a popular product with a newer version just did not generate good publicity, despite the fact it may have been new and improved. And removing the dual inputs was disappointing to many. So it sounds like possibly a good product plagued by bad marketing and poor description. Because for certain applications, the moderate gain CM-7778 version may be more than adequate, and it also has the new design.

TVGOS going for DFW?
I noticed yesterday there was no listing for next Tuesday.
Today, there is no listing for next Tuesday and Wednesday.

Yes I see no further guide listings past 4 AM Tues 2-19. Looks like the end for DFW .

Rovi really picked up the pace on these disconnects after the holidays, with D.C., Houston and San Francisco all gone in the last few weeks, and now DFW going away.

Update: L.A. gone too. I wonder if there's really anyplace where TVGoS will last until April, or was the April drop-dead date that Rovi claimed just "spin?"
Edited by JHBrandt - 2/14/13 at 11:39am

With TVGoS going away Tues. AM, I peeked around my Pal DVR's guide today to see if any stations were sending out more data than what's left from TVGoS.

I found KERA/13 and KDAF/33 both send out about 3 days of guide data via PSIP. Good, but KXAS/5 beats them both. Their guide went all the way to next Thursday (5 days)!

I guess we will have to start an email & phone call campaign to get the rest to post up more days of information. 5 days-worth across the board would be great!

At your suggestion I Googled KitzTech, and after reviewing their offerings I decided to try the less expensive ($50) KitzTech 100. It has variable gain (0-20 dB) and a noise figure of 1.0 dB.

It arrived in the mail quickly, and I was able to test it and confirm that it worked. However it had a couple of drawbacks that initially prevented it from outperforming the AntennaCraft:
1. No FM trap.
2. Although they offer a model with coax-fed power, it doesn't have a weatherproof housing, so it must be installed indoors.

Without the weatherproof housing I saw no advantage in paying an extra $10 for coax-fed power, so I bought the cheaper wall-wart-fed model. (The coax-fed option might be useful if someone were installing a KitzTech in their attic but had no power there.) I also replaced my antenna lead-in cable with a shorter 25' cable to minimize losses before hitting the amp.

Also, I installed an HLSJ just ahead of the amp to serve as an FM trap. Of course, that means I won't receive anything on VHF-Lo (such as KSFW or KXDA if they ever sign on); but that's hardly a big loss.

With those adjustments, the KitzTech 100 does indeed outperform the AntennaCraft and I was able to install it permanently today. Performance is very nearly as good as my old CM-7777 despite the 25' lead-in cable. I'm getting every local channel now, including the troublesome K25FW and KATA/50. I do get occasional breakups on KATA but other stations are fine.

Finally, analog channel 22 is only slightly snowy now. Here it is with the KitzTech:


As a reminder, here's how it looked with the AntennaCraft:


Conclusion: The AntennaCraft 10G212 is a good choice for an easy install. Just hook it up, set the FM trap switch in or out as desired, and adjust the gain for the best picture.

For better performance on the weakest stations, the KitzTech 100 is a better choice; but you'll need to supply your own FM trap and put in the shortest antenna lead-in cable you can get away with.

I should also mention two stations that were never on TVGoS, so we've always had to rely on PSIP for their guides:

KPXD/68 broadcasts about 24 hours
KTXD/47 broadcasts the minimum (12 hours). I think we should email them first. Mention that Cozi broadcasts a guide ten times longer than theirs

I also noticed several LPTV stations broadcast 12 hours, although none of them fill it in with actual programs, as far as I could tell (they just broadcast 12 hours of "TBA")

Low-power KATA/50 seems to be sending PSIP now. For a very long time they had operated with no PSIP data at all, but after I changed my amp and added it back earlier today, I saw both the dummy "TBA" guide and channel labels that hadn't existed before.

Update: With TVGoS completely gone now, these are the only DFW-area stations I can find broadcasting 24 hours or more guide info via PSIP:
KXAS/5 (NBC) - five (!) days
KTVT/11 (CBS) - one day
KERA/13 (PBS) - three days
KDFI/27 ("My 27") - one day
KDAF/33 (CW) - three days
KPXD/68 (Ion) - one day

Everyone else seems to be at the 12-hour minimum. (Keep in mind you may see an hour or two less, depending on when you check.)

One surprising thing is the differences between co-owned stations. KDFI broadcasts 24 hours but KDFW only broadcasts 12, and KTVT broadcasts 24 hours but KTXA only broadcasts 12. WTF?
Edited by JHBrandt - 2/21/13 at 9:04am

I inquired about a month ago with K31GL specifically 31.3 HOT, 31.4 RTV about getting any PSIP listings. Not likely any time soon but hope to add it someday. Cost was the reason. They cannot work it into the budget, need to sell more ad time.

Hot TV and RTV are listed on Zap2it.com (although oddly, WMC doesn't download those listings) so the data is available. The problem is probably that they are buying time on brokered stations. Unless they provide their own encoder, they'd have to get Mako to enter the data into channel 31's encoders. Probably a service Mako provides for a fee, and it wouldn't surprise me if the fee goes up if you want to send more hours of guide info.

"TBA" in the guide is the default output of Linear-branded encoder/multiplexers, so I would guess KATA-CD has installed some new gear.

- Trip

With TVGoS completely gone now, these are the only DFW-area English-language stations I can find broadcasting 24 hours or more guide info via PSIP:
KXAS/5 (NBC) - five (!) days
KTVT/11 (CBS) - one day
KERA/13 (PBS) - three days
KDFI/27 ("My 27") - five days
KDAF/33 (CW) - three days
KPXD/68 (Ion) - one day

Other full-power English-language stations all seem to be at the 12-hour minimum. (Keep in mind that because PSIP guide info is sent in 3-hour blocks, you may see an hour or two less than what the station sends, depending on when you check.) We should thank the KXAS engineers for providing so much guide, and harangue KDFW, WFAA, KTXA, and KTXD for only providing the bare minimum.

One surprising thing is the differences between co-owned stations. KDFI broadcasts 24 120 hours but KDFW only broadcasts 12, and KTVT broadcasts 24 hours but KTXA only broadcasts 12. WTF?

Edit 1: I should clarify I didn't look at religious (KDTN/KDTX) stations' guides.

Edit 2: Just rechecked this evening and was surprised to find KDFI/27 is now on par with KXAS/5, with 5 days of listings!
Edited by JHBrandt - 2/21/13 at 7:43pm

I've sent emails to KDFW 4, WFAA 8, and KTVT 11 asking them to add more days of PSIP, referring to KXAS's 5 days and KERA's 3 days as examples. So far only response is the email from WFAA postmaster failed. They're not even maintaining the functionality of links on their web site.

I'll email as well. I'm not sure how big the intersection between "AVSForum readers in DFW" and "owners of DVRs like the Pal and TViX, that rely on guide data broadcast by the stations rather than a subscription" is - it's probably pretty small - but in case there are others besides Ed and myself, here's what I found so far:

Contacting stations can be a challenge if you don't know who to talk to. KDFW and WFAA have contact forms on their web sites at http://www.myfoxdfw.com/category/233064/about-us and http://www.wfaa.com/on-tv/contact respectively - but if you'd rather call, WFAA lists no phone numbers and I'm not sure which of KDFW's many listed telephone numbers to use. Perhaps 'TV Reception Problems' will reach an engineer? If not perhaps the main station directory, assuming you can get a human operator.

KTXA's contact page at http://dfw.cbslocal.com/station/txa-21/ looks a bit more manageable, but I noticed the emails go to KTVT. (Their web page also makes my browser very sluggish, and you wouldn't believe how hard it was just to get that link pasted.) Of course it wouldn't hurt if both stations increased their guide info, but if anyone calls or writes about KTXA specifically, make sure you mention KTXA at the start.

KTXD's web site lists an email address and phone number at the bottom left of each page. Try http://www.ktxdtv.com/category/232466/about-ktxd and scroll down to the bottom banner.

It'll be interesting to see if anyone responds and what they say.

Edit 1: Here's the email I sent KDFW:
I sent similar emails to WFAA and KTXD.

Edit 2: Email to KTXD bounced. The other two seem to have gone through (I used the web forms for those), but I haven't gotten a response.
Edited by JHBrandt - 2/22/13 at 1:37pm