[RFI] FW: [ntcc] RE: IARU - NN5T
w5gn at mxg.com
w5gn at mxg.com
Tue Aug 5 16:14:08 EDT 2014
From: ntcc at yahoogroups.com [mailto:ntcc at yahoogroups.com]
Sent: Tuesday, August 05, 2014 2:27 PM
To: ntcc at yahoogroups.com
Subject: [ntcc] RE: IARU - NN5T
Problem status update ---
1. RE: Time Warner Cable RF Leak
Their technician has been working since yesterday, and finally came up to
the conclusion. I will confirm if the fix is permanent now.
Initially they sent another technician about 3 weeks ago, and found no problem.
They brought a new test equipment ~ basically portable spectrum analyzer.
The analyzer is connected to 5 element Yagi (700-800MHz) and sweeping the middle of 700MHz range.
The technician told me that every Time Warner Cable truck is equipped with 120MHz receiver that is where the main envelope on Time Warner Cable RF signal is (you can easily identify with the magnet mount 1/4 wave mobile
whip). When any RF leak is detected, the report is automatically sent to
their office as subject for maintenance.
He has been driving around my QTH and found no RF leakage.
The last technician stopped the RF source on Hillcrest to our street and could not stop the RF interference signal.
The technician told me that the reason for detecting the 700MHz RF signal is
because unique to AT&T U-verse. If they detect the RF leak at 700MHz
range, the source is not Time Warner Cable but AT&T. But in my case, the
700MHz signal was peaking at Time Warner Cable distribution box !
The technician has been disconnecting the old and unused B-cable, and
replacing in-line RF amplifiers. He ran the temporary main RF cable in the
case the cable is damaged under the ground. (FYI: my QTH's all utilities
are under-ground including the power line.) No sign of the improvement.
Then finally he replaced the RF shield box for the Motorola RF in-line
amplifier. The 700MHz signal disappeared completely!
He thinks that the slight gap on the shield case was picking up the U-verse signal and Time Warner Cable was reacting as the radiator.
I heard the similar story in the repeater intermod, if the repeater RF amplifier does not have a good shield and if the intermod signal gets into the younger stage on the RF amplifier, you will have a strong intermod signal regardless the receiver IMD performance because the intermod is not generated within your receiver - rather the actual signal is sent onto the air.
Anyway, if you have any Time Warner Cable RF issue, following is the good
contact information. Calling their general Customer Number will get you to
the DU1 land, and they just don't understand the 'RF'.
Time Warner Maintenance Department ~ cable service problem 972-742-5892
2. RE: My RF is getting into AT&T U-verse box (and losing TV, Telephone
and Internet connection) if operated on 160/80/40 200 Watts
Initially the issue on 160 and 40 was resolved by adding the current choke
at the bottom of Butternut vertical. I bought a Balun Designs Model 1116U.
The unit performed OK as current Balun but VSWR went up in a few weeks and
realized that the unit inside was full of water. Determined that this
model is only splash proof ~ not water proof.
It was much easier for me to create the new current Balun with coax rather
than fixing the water leak issue on Balun Designs. Based per G3TXQ's
information, I wound RG-213 around 4 inch PVC pipe 30 turns. No concern
about the water getting into the box. This current choke worked as good as
Balun Designs and doing the good job at the low HF bands including 160.
OK, now no problem on 160 and 40 but I still lose AT&T U-verse if I transmit in between 3.500 ~ 3.510 with more than 100 Watts.
Initially I was suspecting the VSWR (1.7 @ 3.500, 1.4 @ 3.516, 2.0 @ 3.544) and since I was going to figure out how I could switch the 80 meter portion for 75 meter Phone operation (tap on the coil and switch as I was doing with Hy-Tower), I was thinking to add remote antenna tuner to the feed point of HF2V (with 10MHz kit).
Both HEINZ BOLLI and Array Solutions models are so expensive. SGC model
does not have multiple memory design so that I must retune the tuner every
time when I QSY within the band. And all other do not handle 200+ Watts.
I made an inquiry to LDG even they don't make the remote tuner which handles
200 Watts if their AT-1000Proll memory works to meet to my requirement, and they told me to go with SGC.
Personally I disappointed MFJ's quality big time in many years ago, I was
not even looking at MFJ models. But since I am now using Cushcraft R-6000
by MFJ (and really no other choice), I decided to look into their remote tuner.
I just did not want face any arcing, I picked MFJ-998RT even I could go with
MFJ-993 or -994. 1.5kW SSB/CW, 12 to 1,600 Ohm matching range. Unit does
not require separate DC power line nor control cable. But important
enough, I can setup the memory in small steps within the band.
Per SPEC, you can setup the memory in 0.2% step of operating frequency which
is in 2kHz step on 160, 4kHz step on 80/75, and 7kHz step on 40. Now my
rig sees better than VSWR 1.3 in 1,800 ~ 1,880, 3,500 ~ 3,910, 7,000 ~
7,300. Won't tune above 1.880 nor 3.910MHz, but it is OK.
To make long story short, I still have AT&T U-verse issue in lower edge in
80 meter CW. It is going to be tough 80 with reduced power.
From: Jon Suehiro [mailto:nn5t at attglobal.net]
Sent: Sunday, July 13, 2014 3:39 PM
To: 'ntcc at yahoogroups.com'
Subject: IARU - NN5T
I have not checked WRTC stations but already sent the log to both IARU and
WRTC wants to 'iaruhf at arrl.org' and ARRL rule says 'IARUHF at iaru.org'.
Received 2 separate 'same' robot replies.
AT&T U-verse box will reset on 160 and 80 when VSWR on Butternut HF2V
exceeds 1.5. I already have ferrites at the AT&T twin wire input and 2
current chokes on both antenna and rig ends. The antenna tuner at the rig
end did not help so planning to add remote tuner at the bottom of the
Time Warner cable leaks on and off in 5 ~ 60MHz. Completely wipes off
7/14/21 with S=9+ burst signals. Activity related ? The worst time is
typically in 9 ~ 11 am and 2 ~ 6 pm. Already located the bad section in
buried cable and distribution boxes in driveway and called but they are
slow. Took me 1 hour to explain the RF leakage into HF band and what the
short wave listening or ham radio is.
CLUB: North Texas Contest Club
CREATED-BY: WriteLog V11.21P
QSO PTS ZN HQ
80CW: 25 55 6 4
40CW: 153 417 15 17
20CW: 185 563 22 30
15CW: 51 141 10 15
10CW: 8 24 4 3
Total: 422 1200 57 69
Total Score = 151,200
Posted by: "Jon Suehiro" <nn5t at attglobal.net>
All replies will go to the NTCC list.
New Messages to NTCC at yahoogroups.com
Send a blank message to NTCC-unsubscribe at yahoogroups.com
Yahoo Groups Links
<*> To visit your group on the web, go to:
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
(Yahoo! ID required)
<*> To change settings via email:
ntcc-digest at yahoogroups.com
ntcc-fullfeatured at yahoogroups.com
<*> To unsubscribe from this group, send an email to:
ntcc-unsubscribe at yahoogroups.com
<*> Your use of Yahoo Groups is subject to:
More information about the RFI