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CATV RF Notch Filter

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Guest

Thu Feb 26, 2015 8:59 pm   



Hi,

I am looking for a source where I can buy an RF notch filter for CATV.

One source I found via Google is tinlee.com

I sent an email to sneva_at_tinlee.com. Later that same day, I received a
reply!!!

In the reply I was asked for more details regarding what I want
(specs) in the filter. I told Sneva the frequency (276Mhz), etc. I have not
received another reply. I sent another email to Sneva, but still no reply.

I asked Sneva if he (assumed) can't make the filter, please let me know
so I can look for another source. Still no reply.

Can someone recommend another CATV RF notch filter source?

Thank You in advance, John N3AOF


Guest

Fri Feb 27, 2015 8:48 pm   



Quote:
I am looking for a source where I can buy an RF notch filter for CATV.

One source I found via Google is tinlee.com

I sent an email to sneva_at_tinlee.com. Later that same day, I received a
reply!!!

In the reply I was asked for more details regarding what I want
(specs) in the filter. I told Sneva the frequency (276Mhz), etc. I have not
received another reply. I sent another email to Sneva, but still no reply.

I asked Sneva if he (assumed) can't make the filter, please let me know
so I can look for another source. Still no reply.

Hi,
UPDATE:

I finally received a quote, $185.00 plus $20.00 shipping. Since this
filter has to be custom made, the price is high.

John

J.B. Wood
Guest

Mon Mar 02, 2015 7:27 pm   



On 02/26/2015 08:59 AM, jaugustine_at_verizon.net wrote:
Quote:
Hi,

I am looking for a source where I can buy an RF notch filter for CATV.

One source I found via Google is tinlee.com

I sent an email to sneva_at_tinlee.com. Later that same day, I received a
reply!!!

In the reply I was asked for more details regarding what I want
(specs) in the filter. I told Sneva the frequency (276Mhz), etc. I have not
received another reply. I sent another email to Sneva, but still no reply.

I asked Sneva if he (assumed) can't make the filter, please let me know
so I can look for another source. Still no reply.

Can someone recommend another CATV RF notch filter source?

Thank You in advance, John N3AOF

Hello, and I have to ask - What do want to do with it? These filters
were used back in the 80s on analog CATV systems at the subscriber's
location to allow for authorized reception of premium channels such as
HBO and Cinemax. If you tried to view these channels without the filter
all you got was garbage on the screen and most often no discernible audio.

For their intended purpose the notch filters would be useless on today's
digitally encrypted systems. Most of the filters I've seen were mounted
in a metal cylinder with type F connectors on either end. They were
inserted between the incoming CATV RF cable and the set-top box. They
could also be installed within a distribution box in apartment
complexes. Sincerely,

--
J. B. Wood e-mail: arl_123234_at_hotmail.com

Don Bruder
Guest

Mon Mar 02, 2015 10:48 pm   



In article <md1kv7$cf8$1_at_ra.nrl.navy.mil>,
"J.B. Wood" <arl_123234_at_hotmail.com> wrote:

Quote:
On 02/26/2015 08:59 AM, jaugustine_at_verizon.net wrote:
Hi,

I am looking for a source where I can buy an RF notch filter for
CATV.

One source I found via Google is tinlee.com

I sent an email to sneva_at_tinlee.com. Later that same day, I
received a
reply!!!

In the reply I was asked for more details regarding what I want
(specs) in the filter. I told Sneva the frequency (276Mhz), etc. I have
not
received another reply. I sent another email to Sneva, but still no
reply.

I asked Sneva if he (assumed) can't make the filter, please let me
know
so I can look for another source. Still no reply.

Can someone recommend another CATV RF notch filter source?

Thank You in advance, John N3AOF

Hello, and I have to ask - What do want to do with it? These filters
were used back in the 80s on analog CATV systems at the subscriber's
location to allow for authorized reception of premium channels such as
HBO and Cinemax. If you tried to view these channels without the filter
all you got was garbage on the screen and most often no discernible audio.


As I recall having a cable tech explain it to me back when they were in
use, you've got it exactly reversed - you REMOVED the filter to get the
premium channel, because it was tuned to block that channel. Which is
why they were generally installed either up on the pole, or in a
(usually locked and/or tamper-sealed) box where Joe User couldn't get to
'em.

For the first year or so after our local CATV system went in, it was
easy to tell which of the subcribers got one or more of the four
available premium channels our system carried - HBO, Showtime, Cinemax,
and Playboy - because the filters hung right off the cable at the pole:
If you got HBO, your wire *DID NOT* have a "short green" can on it. If
you got Cinemax, the "long silver" can wasn't on your wire. If you got
Showtime, the "short silver" can was missing, and if you got the playboy
channel, the "fat red" can wasn't there. All four cans meant you were
one of the "po' folk", getting just basic cable service. No red can on
your wire meant you regularly got leafletted by the local "pornography
is evil" minions. Which, I think, was probably a contributing factor in
the move to housing the filters in sealed/locked/tamper-proof boxes at
the point where the cable went into the house starting in the second
year after the system went live.

--
Security provided by Mssrs Smith and/or Wesson. Brought to you by the letter Q

J.B. Wood
Guest

Tue Mar 03, 2015 6:24 pm   



On 03/02/2015 10:48 AM, Don Bruder wrote:
Quote:
In article <md1kv7$cf8$1_at_ra.nrl.navy.mil>,
"J.B. Wood" <arl_123234_at_hotmail.com> wrote:

On 02/26/2015 08:59 AM, jaugustine_at_verizon.net wrote:
Hi,

I am looking for a source where I can buy an RF notch filter for
CATV.

One source I found via Google is tinlee.com

I sent an email to sneva_at_tinlee.com. Later that same day, I
received a
reply!!!

In the reply I was asked for more details regarding what I want
(specs) in the filter. I told Sneva the frequency (276Mhz), etc. I have
not
received another reply. I sent another email to Sneva, but still no
reply.

I asked Sneva if he (assumed) can't make the filter, please let me
know
so I can look for another source. Still no reply.

Can someone recommend another CATV RF notch filter source?

Thank You in advance, John N3AOF

Hello, and I have to ask - What do want to do with it? These filters
were used back in the 80s on analog CATV systems at the subscriber's
location to allow for authorized reception of premium channels such as
HBO and Cinemax. If you tried to view these channels without the filter
all you got was garbage on the screen and most often no discernible audio.

As I recall having a cable tech explain it to me back when they were in
use, you've got it exactly reversed - you REMOVED the filter to get the
premium channel, because it was tuned to block that channel. Which is
why they were generally installed either up on the pole, or in a
(usually locked and/or tamper-sealed) box where Joe User couldn't get to
'em.


Hello, and actually we're both correct. There was "negative" and
"positive" trapping. The technique I previously described involved the
insertion of an narrowband interference signal in the premium channel
passband by the CATV provider. Therefore only those with the notch
filters would get viewable premium channels. The other way that you
described required all non-subscribers to the premium channels to have
band-reject filters. Sincerely,


Guest

Tue Mar 10, 2015 1:20 pm   



On Fri, 27 Feb 2015 08:48:15 -0500, jaugustine_at_verizon.net wrote:

Quote:
I am looking for a source where I can buy an RF notch filter for CATV.

One source I found via Google is tinlee.com

I sent an email to sneva_at_tinlee.com. Later that same day, I received a
reply!!!

In the reply I was asked for more details regarding what I want
(specs) in the filter. I told Sneva the frequency (276Mhz), etc. I have not
received another reply. I sent another email to Sneva, but still no reply.

I asked Sneva if he (assumed) can't make the filter, please let me know
so I can look for another source. Still no reply.

Hi,
UPDATE:

I finally received a quote, $185.00 plus $20.00 shipping. Since this
filter has to be custom made, the price is high.

Hi,
FINAL UPDATE:

I received the filter from Tin Lee Electronics. This filter removed
the streaming promos that ANNOY me. The results, with the promos
"removed", when I go to "On Demand" (a small delay occurs), now
I see whatever channel I was viewing, instead of promos. This
can be handy when commercials come on, and I can check what
is "on demand" during commercials of a program I am watching.

With my signal generator, I corrupted the streaming video to
the degree it could not be decoded. The filter removed the signal.

John

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