TVI Anyone ?

[w5hro]

Well, I'm still unpacking boxes and I came across two of my Drake TVI low pass filters. One is the TV-1000 in the old copper chassis and the other is the TV-3300. The TV-1000 has never been used and was still sealed in its original box when I found it. I remember placing both of them on an IFR spectrum analyzer and they had really sharp roll-off above 50Mc with great attenuation from that point on. From what I remember the newer TV-3300 had slightly better characteristics and it’s roll-off started a bit lower somewhere right after 30Mc. I think it was once rated one of the best if not the best TVI filters ever made.

Anyone have any spec sheets or info on these babies?

[Steve - WB3HUZ]

Google is your friend.

http://www.wb4hfn.com/DRAKE/DrakeArticles/LPF3300.htm

[Ed/KB1HYS]

Does anyone actually used one of these in there shack today?  I have an EF Johnson version, but never used it as I thought they were finicky about the load they fed into (50 ohms).

[k4kyv]

With so many TV's now on cable or satellite, harmonic TVI is much less a problem than it used to be.  RF overload (faulty design of cheap consumer junk) is now more of a concern.  Even with rooftop antenna reception, harmonic TVI may be  less of a problem once the digital transition occurs, since the worst offenders, the low-band VHF channels will be taken out of service and everything shifted to channel 5 or higher, or to UHF.

I heard the other day that the House failed to pass the proposed delay of the digital  conversion until June.  Right now it appears that it will occur in February as planned.

[KM1H]

I use Johnsons behind both TS-940's and into amps. Had to put one on the VNA and tweak as someone was messing around with it. Other than that they look excellent on the VNA and TS-940 VSWR meters. Got some copper box Drake on the Viking I and use ICE 421's on all amps, AM or SSB/CW.

Last I read, Comcast didnt even have 80% penetration in this town but that was a few years ago. I can run any band HF to microwave at any time and havent had a TVI call in years.

As far as DTV, dont hold your breath. The House will bring it up again next week or so probably with revisions to get it passed.

CH2 -5 will still be used by up to 7 stations, the industry lobbied that way to preserve the spectrum.....for now at least.

I was hoping for a 70 mHz ham allocation. It may still be possible under a secondary, no interference, type of allocation.