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Very poor results from HD7698P

14K views 58 replies 7 participants last post by  Cham 
#1 ·
Have had this antenna for a few years. Originally installed it on the roof with a tripod and worked well picking up local and distant US stations to the south. We had the roof re-done, and it has been in storage for 2-3 years. Meanwhile I have been using an old VHF log periodic on a tower nearby with two HDHomeRuns, one connected to the log periodic for dx, the other on a 4-bay bow-tie pointing north for locals.

I finally got the HD7698P up in place of the log periodic up about 40' on the tower, new feedline and I had also replaced the Wingard balun (part of the antenna) since it looked to be corroded, didn't want trouble.

With the fancy Wingard antenna up on the tower I could only get CKY and KNRR (both within 30-40km. Nothing else! Seems dead as a door-nail! Would get better reception with a wet noodle. If I pointed it north right at Winnipeg I could scan in CBC but it blocks and fades out sporadically.

CKY is about 40km away antenna pointing right at it!:
Modulation Lock 8vsb
Signal Strength 61%
Signal Quality 90%
Symbol Quality 100%

Brought the tower down and put the log perodic back on and reception is back the way it was.

Checking the HD7698P I find no shorts in the vhf and uhf elements, good continuity between connected elements etc. Not finding anything wrong with the antenna itself. Nothing obvoius with the balun/circuit board. Seems electrically the same as the old one (continuity checks etc). I didn't check operation with the old balun (yet) though. Connection between UHD and VHF conductors at the balun seems fine.

I must be missing something... likely an issue too obvious for me to see...! Where else should I look? Any ideas appreciated.

Was looking forward to better UHF reception to the south. :(
 
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#3 · (Edited)
With the fancy Wingard antenna up on the tower I could only get CKY and KNRR (both within 30-40km. Nothing else! Seems dead as a door-nail! Would get better reception with a wet noodle. If I pointed it north right at Winnipeg I could scan in CBC but it blocks and fades out sporadically.

I must be missing something... likely an issue too obvious for me to see...! Where else should I look? Any ideas appreciated.
You have to suspect the balun.
I also suspect the CB-8269 balun.

Winegard has a troubleshooting video. The idea is to check each section of the antenna with a conventional balun clipped to each set of wires for UHF and VHF.
How To Troubleshoot a Winegard Antenna Cartridge Housing
https://www.youtube.com/watch?v=TlQke5QYbng







 
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#4 ·
I was wondering if some of the more knowledgeable members of the forum might be able to answer a question for me. I am interested in taking the feed from my antenna system and hooking it into a "box" which would then distribute my signal wirelessly to the various TV's and computers in my home. It sure would save a lot of time running coax all over the house which would be somewhere between difficult and impossible. Is there such a magic box? can I use an old computer modem? Just thinkin.....
 
#7 ·
Ok, guess I'll have to pull the antenna down and do this check. Always have a few regular baluns around. It's a brand new CB-8269 but of course that doesn't mean it works. If nothing is grounded or shorted in the antenna harness or elements that would indicate only one likely possibility (unless the feedline or connector(s) is bad). Thank you for the information @rabbit73 and @Red Knave.
@fgt I use two HDHomeRuns and find they work relatively well. I use an Extend for nthe DX antenna (not working great right now) and a Connect for locals. It is likely a good idea to have ethernet with gigabit capability so there is lots of bandwidth headroom in your LAN even if they are 10-100 connections. I use one TV that uses wireless to connect to the LAN but it is 5.8HGz, I find the 2.4 wifi doesn't work as well. I am using a Uniquiti UniFi AP-AC-Mesh radio as an AP and it works really well. There are other options for network receivers that may be as good or even better, but these have worked well for me.
 
#8 ·
Well I pulled down the tower and antenna yesterday and checked as I did before putting the antenna up initially and it seems perfectly fine. No shorts or opens as I checked between where the balun fits in to the "harness" and elements it connects to. Nothing out of the ordinary. Connected the cable via the original balun to the UHF elements and I get nothing on the ground. Connected to the VHF harness and I get 7 and 12 like when up on the tower. When the antenna is "down" it is in a treed yard and I don't expect to get much reception, especially on UHF.
Just for fun I left the alligator clips attached to the UHF element harness and put the antenna on the roof. Now I get CBC out of Winnipeg but nothing else (antenna is pointed south away from CBC) which indicates it is likely working.
Thinking the balun/combiner is no good. I just spent $60 getting a new one and I have no incentive to spend another $60 on another one. Thinking I could invest in two 75 - 300 ohm baluns and use a separate combiner? Just have to make something up to connect the balun 300 ohm leads Cu) to the antenna harness(s) which is aluminum that won't react (galvanic). Maybe silver plated alligator clips?
It's a lot of work to take the tower up and down so I hope to do it once....!
 
#9 · (Edited)
Instead of Alligator Clips, perhaps you need something more permanent, such as fol. "Split Bolt Connectors", suitable for AWG14 thru AWG8:
https://www.amazon.com/SPLIT-BOLT-SERVIT-MfrPartNo-KS15RK/dp/B000H5XXHK

Alternatively, you might want to try some "T-Tap Splice Connectors", such as following [up to AWG10], which I only saw coming with a MALE SPADE type connector. At your local Auto Parts store, perhaps you can find some with a CRIMP type connector (instead of Spade Lug) for improved reliability. I would also recommend that you wrap the connection (and Baluns) with electrical tape to immobilize them so they don't move in the wind. [Use micrometer to measure your Antenna connector Wire Size to determine a compatible T-Tap size....apparently only available up to AWG10.]
 
#10 ·
@holl_ands,
Never thought of those type of connectors, great idea!
Can use that anti-corrosion goop used for aluminum cable in copper clamps such as inside breaker panels etc.
I can use the original enclosure to help support/protect the baluns, there should be quite a bit of room without the circuit board. Maybe self-vulcanizing tape would be good to use along with the electrical tape as well.
Do you have any recommendations on combiner? Is there a minimum distance form the baluns for placing it?
 
#11 ·
#12 ·
Well, finally got to do some antenna work. I already had a mast-mount VHF/UHF combiner so I used it, put everything back up and found no appreciable difference in signals, still very poor. After some head scratching I realized I had not tried another receiver on that antenna. I also have a HDHomeRun Connect, so I switched them around. Now I get all the channels I was expecting anf the Extend on the bow-tie picks up the local CKY transmitter a few miles away and that's it. Guess it's receiver is almost dead... sensitivity is very poor.

I feel kind of stupid though not trying this earlier. Problem likely had nothing to do with the antenna, combiner, or feedline.
Odd thing is the old log-periodic I put back up seemed to work (but lately not that well either).

Now another problem... after a few days the Connect is losing channels on that same antenna. Was getting WDAZ and KX4 as well as cityTV off the back, now they are gone and signals from 12, 7, Global and CBC (off the back on UHF) are down considerably. It is like something is overloading the receiver to the point it could be damaging the front-end circuitry? It is currently dis-connected and I hope I haven't damaged it too!

I do have my amateur radio station nearby (hundred meters or so), and have a VHF transmitter to utilize the local repeater at about 146MHZ, and another digital transmission at 144MHz, both at rarely more than 5 watts. My HF station can go as high as 1KW but that is a long way frequency-wise from the television broadcast bands (1.8-21MHz).

I don't have a spectrum analyzer to monitor a wide band of RF, and I would be concerned leaving one attached to a feedline that could overload it, but one could just ramp up attenuation I suppose. Any ideas what I should be looking for here?

-C.
 
#14 · (Edited)
After some head scratching I realized I had not tried another receiver on that antenna. I also have a HDHomeRun Connect, so I switched them around. Now I get all the channels I was expecting anf the Extend on the bow-tie picks up the local CKY transmitter a few miles away and that's it. Guess it's receiver is almost dead... sensitivity is very poor.

I feel kind of stupid though not trying this earlier. Problem likely had nothing to do with the antenna, combiner, or feedline.
Odd thing is the old log-periodic I put back up seemed to work (but lately not that well either).

Now another problem... after a few days the Connect is losing channels on that same antenna. Was getting WDAZ and KX4 as well as cityTV off the back, now they are gone and signals from 12, 7, Global and CBC (off the back on UHF) are down considerably. It is like something is overloading the receiver to the point it could be damaging the front-end circuitry? It is currently dis-connected and I hope I haven't damaged it too!
Hello, Cham

That was a good idea to try another tuner when you had exhausted the possibilities in the antenna system. The tuner could be failing, but it could also be the power supply for the tuner failing, as in these two reports:
https://www.digitalhome.ca/forum/81-over-air-ota-digital-television/191274-hdhomerun-ota-discussion-12.html#post2421569
.....I did also post my current issue at SiliconDust forums and got the clue I needed... My issue was that my 5V power supply on the the SD HDHomeRun has started to go bad (it is 6-7 years old I guess having been powered on 24/7 all that time). This is not obvious at all! I simply never would have guessed that, even though I've replaced my fair share of bad power supplies before... But I had green LEDs going, and most all my channels in fact did work, except for most all of my strongest local stations (ie. CBLT, CITY, etc.). While local channel CTV actually did work the whole time for some reason...

In any event, I swapped in a new 5V power supply and presto, my CBC and other local channels are back!

So note to the wise, if things are behaving mysteriously erratic, check all you power supplies!

Problem solved. Thanks! -Glenner.
jsiddall said:
100% signal strength, no lock
I am having a hard time getting a set of local OTA HDTV channels from a specific tower about 15 miles away.

Signal strength shows 100% but still no lock and no picture, or a heavily pixelated picture.

UPDATE 4: I bought a cable long enough to run the antenna to a different floor where I had another tuner and that tuner worked great on all channels. Perfect quality. So having narrowed the issue down to the HDHomeRun I swapped out the power supply and problem solved. Signal strength is the same but lock happens immediately and the picture is flawless. Gaah. I hate SMPS and all the time I have wasted on them over the years. This one was a bit strange because so much of the tuner was working fine (like the network stack and parts of the RF chain) but clearly some RF stuff was out to lunch.
https://shop.silicondust.com/shop/?_ga=2.63471215.1955827834.1572724099-708569114.1572097742
Click on Replacement Parts
I don't have a spectrum analyzer to monitor a wide band of RF, and I would be concerned leaving one attached to a feedline that could overload it, but one could just ramp up attenuation I suppose. Any ideas what I should be looking for here?
Try replacing the HDHR PS first. If that doesn't help, make a spectrum analyzer with a $20 SDR dongle and spectrum analyzer software:



Channel 9 is marginal, with just barely enough SNR above the noise. My HDHR4-2US Connect Duo does slightly better than my 32" Sony on that marginal channel:





Unfortunately, the HDHR tuner maxes out at 0 dBmV for 100%, even though TV tuners can handle stronger signals. In order to determine how strong a signal is above 100%, use a step attenuator to bring the signal down to 100%. The reading on the attenuator is how much stronger the signal is than 0 dBmV. If you don't have a step attenuator, use a series of inexpensive fixed attenuators of 3, 6, 10, and 20 dB. Even a splitter as an attenuator would give you a rough idea.
 
#13 ·
What was the receiver you had problems with, the one ur later saying may be poor sens?
Do you have an old computer or (or even a raspberrypi), that can run linux?


see some of my posts in the signal analyzers thread for some low cost but effective measurement ideas.
https://www.digitalhome.ca/forum/81...aimers-bench-gear-diagnostic-software-22.html

had to do some antenna work myself yesterday AM. With all the recent windstorms, one of my antennas slipped,
and just so happened every time I looked at it from the ground, I couldn't quite tell what was up with it, cause it was always dark out
at the time I was eyeballing. Finally had some leisure time with the sun out yesterday and fixed it.
 
#15 ·
and that is why we interpolate from a straight line the strength and snr beyond 100% in
905shmick's bash script. I find it's fairly accurate.

https://github.com/shmick/TV_Stuff
 
#16 · (Edited)
That would be extrapolate:
extend the application of (a method or conclusion, especially one based on statistics) to an unknown situation by assuming that existing trends will continue or similar methods will be applicable.
I see that, but I don't know how to use it; it doesn't list signal strengths any higher than 0 dBm/-48.75 dBmV. And, I don't know where to look in the software for this:

Sorry the report was from the SE facing HDHR4/C2V/Juice setup.

Here's the result for RF20 on the HDHR4:

tun: ch=auto:20 lock=8vsb:509000000 ss=100 snq=61 seq=100 dbg=-3975/-7079
dev: bps=19530944 resync=0 overflow=0
ts: bps=19530944 te=0 miss=0 crc=0
net: pps=0 err=0 stop=0
And I wouldn't know how to use this and I don't know where to look in my HDHR4 software for dbg numbers:

here is a patch to 905shmick's latest script. This adds a 'Debug' option.
When ya run it, it will extrapolate signal strengths > 100% to dBmV and dBm. The assumption here is that the 'dbg=' value from the hdhr3 continues to be linear above SS = 100.

I think it's probably "close enough", since I have read the hdhr can handle an input signal of up to +40 dBmV. But, I have not verified how far the linearity continues beyond 100. So it's still just a guess. Someone with some real test equipment (ie a calibrated ATSC signal generator) can try that excercise.
I put some comments in there to explain what I had done.

http://pastebin.com/nE7BgX3r

It won't work on the hdhr4, since as you noticed the numbers are significantly different. But, I am sure someone could do a similar look at the dbg= vs SS within the hdhr4's usable 0 - 100 SS scale sometime.
I do have a stable signal source and two signal level meters, but I don't have your software talents to find the dbg numbers. I am able to measure the strength of signals with my signal level meter and have calibrated the signal strength scale in my 32" Sony KDL32R400A which goes all the way up to -8 dBm/+41 dBmV (very unusual....one dB per step....the design engineer must have used an RSSI chip), but I would like to know how to find the dbg numbers for my HDHR4.

 
#17 ·
it's all good rabbit...
It is just a Bash script...
If you have a raspberrypi or some other machine running Linux, install the hdhomerun driver/sw from silicon dust, then download the script, set it to be executable, and try it...
It WOULD be interesting to compare it to your test equipment some day.
 
#18 · (Edited)
It is just a Bash script...
Easy for you
Hard for me
install the hdhomerun driver/sw from silicon dust
I couldn't find that

driver?

Is it this:

https://www.silicondust.com/support/linux/

As Jeff Dunham's Peanut says, it's over my head

Whoosh!

I was able to assemble a program folder for the SDR Spectrum Analyzer software, but I think this is beyond my ability.

That still leaves my question unanswered

Where are the dbg values for a channel located?
 
#19 ·
yes rabbit, that is the sw / driver u wanna install in linux.
If you have a debian based system (ubuntu, etc), the required packages are probably in the repo that you can just install from apt.

sudo apt install hdhomerun-config-gui

for the dbg info, follow along what we did in the hdhomerun thread.
goes on for couple of pages +/-
https://www.digitalhome.ca/forum/81...ision/191274-hdhomerun-ota-discussion-13.html
 
#20 ·
yes rabbit, that is the sw / driver u wanna install in linux.
If you have a debian based system (ubuntu, etc), the required packages are probably in the repo that you can just install from apt.

sudo apt install hdhomerun-config-gui
Thank you for showing me the path, majortom.

That is a steep learning curve for this 86 year old guy. I didn't even know what github was until Sept when I needed some open-source sw from it.
 
#21 ·
@majortom, originally a HDHomeRun Connect (HDTC-2US), then I think the newer Connect may have been damages as well. Remember a discussion a while back about an economic SA unit for this sort of thing. Might be an investment to consider. Don't really like borrowing such equipment unless it's really imortant commercial type diagnostics.
@rabbit73, They use seperate power supplies, would be improbable that both would fail in sequence... but not imposssible. Found another p/s last night with the same plug 12v 1.5a rating will try that next.
Might try one of those tuners, thinking of doing that, not as much of an investment as a new HDHomeRun receiver and I have a linux box I can use for that (486 doing distributed computing that heats a room). Might be a bit slow though :) Can find another newer pc I suppose if so..
 
#22 · (Edited)
Using an SDR Dongle as a Spectrum Analyzer

Might try one of those tuners, thinking of doing that, not as much of an investment as a new HDHomeRun receiver.....
The SDR dongle is not designed for reception of ATSC 8VSB, it's for European DVB-T, but can be used as a spectrum analyzer with the correct software.
https://www.rtl-sdr.com/about-rtl-sdr/

https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/

https://www.digitalhome.ca/forum/186-antenna-research-development/287147-converting-uhf-yagi-vhf-antenna-7.html#post3090963

Much less expensive than a conventional SA, and quite adequate for many applications.

For the most accurate display increase the dongle gain until the noise floor just starts to rise, then back off a little.



Dongle gain set correctly, no preamp at antenna. (With a preamp at antenna, dongle gain had to be reduced to about 5 dB.):





This shows very high noise level from electrical interference:



High noise level on VHF-Low. Signal had to be at least -8 dBmV to have sufficient SNR above the noise:



Signal diagnostics:



Channel 3 folded dipole:

 
#24 ·
BTW, I like ur comment relative to the rtlsdr gain...
That is what most newcomers to rtlsdr world fail to realize at first...
What I do in that regard is set it for manual rf gain, and only use enough gain in whatever program,
till I see the noise floor just start to increase, and leave it there. Is usually good starter kit for me.
 
#25 ·
@rabbit73...
I was installing that hdhomerun stuff on an older ubuntu machine, and realized I should have posted the rest of the sauce to get that going for you...


Code:
# make sure the cli version hdhomerun_config is installed
sudo apt install hdhomerun_config
# make sure git is installed
sudo apt install git

# change to ur home directory
cd ~/
mkdir src
cd src
# clone 905shmick's repo
git clone https://github.com/shmick/TV_Stuff
cd TV_Stuff
# Now try to run the script
./channel_scan.sh -D
Output should be something like so..
Code:
16 channels found
RF    Strngth    dBmV    dBm    Quality    SNR    Symbol    dbg    Calc_dBmV    Calc_dBm
--------------------------------------------------------------------------------------------
5    91    -5.4    -54.1    52    17.2    100    -461    -5.7        -54.5
8    67    -19.8    -68.5    43    14.2    100    -578    -22.1        -70.9
14    87    -7.8    -56.5    85    28.1    100    -477    -8.0        -56.7
17    100    0.0    -48.8    89    29.4    100    -223    27.6        -21.2
19    69    -18.6    -67.3    51    16.8    100    -561    -19.7        -68.5
20    71    -17.4    -66.2    65    21.4    100    -549    -18.1        -66.8
25    73    -16.2    -65.0    68    22.4    100    -533    -15.8        -64.6
29    100    0.0    -48.8    98    32.3    100    -284    19.0        -29.7
32    100    0.0    -48.8    88    29.0    100    -351    9.7        -39.1
33    100    0.0    -48.8    65    21.4    100    -350    9.8        -39.0
36    100    0.0    -48.8    68    22.4    100    -303    16.4        -32.4
38    100    0.0    -48.8    56    18.5    100    -354    9.2        -39.5
41    59    -24.6    -73.3    47    15.5    100    -604    -25.8        -74.5
42    63    -22.2    -71.0    55    18.2    100    -584    -23.0        -71.7
43    100    0.0    -48.8    91    30.0    100    -357    8.8        -39.9
49    79    -12.6    -61.4    63    20.8    100    -510    -12.6        -61.4
 
#26 ·
@majortom
Thank you for the additional information. You are two steps ahead of me.

I have to decide whether to dual-boot this machine or get another Windows machine and dual-boot it. I'll probably do the latter so I don't mess up this laptop.

Machines that come with Linux installed seem to be more expensive than Windows machines.
 
#27 ·
Linux can also be installed on a second drive. "Live" distros are installed on a USB flash drive. Just burn the distro to the drive and then boot from it. It's not the fastest way to run Linux but OK for occasional use. Just be sure to use the option (if required) that allows saving modifications between boots.

Linux can also be installed on a Raspberry Pi. Again not the fastest but inexpensive and good for things like this script and applications that don't require a lot of resources. There are preconfigured distros for the Pi that just burn to an SD card. That's what I did.

If all you need is a signal meter, there is an HDHomeRun app for smartphones. It's great for tuning the antenna outside.
 
#28 ·
Thank you for the suggestions.

That would be a lot easier than installing Linux.

I have the signal meter; it's now included in the software instead of being separate as before.



What I would like to see are the dbg numbers for a channel that are in hdhomerun-config-gui for my HDHR4-2US Connect Duo like this:
Sorry the report was from the SE facing HDHR4/C2V/Juice setup.

Here's the result for RF20 on the HDHR4:

tun: ch=auto:20 lock=8vsb:509000000 ss=100 snq=61 seq=100 dbg=-3975/-7079
dev: bps=19530944 resync=0 overflow=0
ts: bps=19530944 te=0 miss=0 crc=0
net: pps=0 err=0 stop=0
In particular, for the signals that are stronger than 100%.



Rather than learning Linux Ubuntu at this point, I was wondering if I could use Command Prompt as a shell in Windows for the numbers.
 
#29 ·
Anyways.. checked both power supplies, they appear to be working well or well within spec.
The Connect works fine on the bowtie antenna (up maybe 12ft) for locals, and works fine for a day or two on the Winegard. The Extend only receives CKY about 18km away, nothing else, no matter what antenna I use.

Would like to try another receiver on that Winegard antenna and see what gives. Still thinking an ATSC dongle and raspberry pi or spare PC? The HDHomeRuns were located inside a nice 6ft 19" rack enclosure with a 16 port switch, power supplies, and battery B/U unit. Have to build a rack mounted PC I guess...
 
#30 · (Edited)
Anyways.. checked both power supplies, they appear to be working well or well within spec.
The Connect works fine on the bowtie antenna (up maybe 12ft) for locals, and works fine for a day or two on the Winegard. The Extend only receives CKY about 18km away, nothing else, no matter what antenna I use.

Would like to try another receiver on that Winegard antenna and see what gives. Still thinking an ATSC dongle and raspberry pi or spare PC?
I don't know of any ATSC 8VSB dongle tuner that is better than the HDHR4-2US Connect Duo. The Channel Master 7004 tuner is just as sensitive as the tuner in my Sony TV, but the HD output is HDMI.

Do you have a TV with a tuner that you can connect to your antenna?

I think you are ignoring a diagnostic tool that would be helpful, the RTL-SDR dongle with spectrum analyzer software. There is a tutorial thread to help with the software assembly.

The advantage of the SA is that it will show a channel even when a tuner scan doesn't pick it up.

My UHF 14-51:



You can scan a shorter section:



These are the signal numbers for 16, 17, and 19:





 
#31 ·
personally I like the USB dongles I have better than the hdhomerun.
'Cause in linux they will report in decibels straight away.
I can get a strength dBm and SNR reading in dB when below the 15 dB lock threshold to judge how far away from a lock I am, to aid in dialing in the antenna. When I do a 'spectrum scan', I just click on an interesting signal in the plot and see if it locks.
Can't do that with the rtl sdr dongles.
From the updateDVB Readme:
Code:
# ATSC devices supporting spectrum scan, blindscan works by having a list of
# possible ATSC transponders and trying those
# Hauppauge WinTV-HVR-950Q
# Hauppauge WinTV-Aero-m
# Hauppauge WinTV-HVR-955Q (iqplot 8vsb & qam)
# Hauppauge WinTV-DUALHD   (iqplot 8vsb & qam)
I addition to those, we have added the mohu a681, and mygica a681...
These work pretty good for this too, albeit the spectrum scan is a bit slower than the
ones described in the Readme.

I own and have personally tested each of those devices, save for the mygica a681, but that is almost identical
to mohu a681 (which I do have), just a different tuner chip inside, same demod. And have seen one user who confirmed his was working.

Some screenshots from the old wiki, note that for the atsc screenshots it's only showing an example of the fast spectrum scan.
But in Slow spectrum scan it will look more like the satellite spectrum scan does, just in the ATSC spectrum obviously
https://bitbucket.org/updatelee/updatedvb.old/wiki/Screenshots
 
#32 ·
#33 · (Edited)
Good question; back to basics.

I must be missing something... likely an issue too obvious for me to see...! Where else should I look? Any ideas appreciated.

Was looking forward to better UHF reception to the south. :(
A signal report would be helpful. "Southern Manitoba" isn't sufficiently accurate for a reception analysis.
traditional report:
http://www.tvfool.com/index.php?option=com_wrapper&Itemid=29
channel list more accurate:
https://www.rabbitears.info/searchmap.php

You might have to use coordinates
 
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