TinLee is very decent on making custom attenuators. I had a quote done up last month for a custom one which would block 32 and 38 but pass channel 35 and I found the price reasonable. I am waiting until warmer weather to purchase it.

Is it Ok if I attach the power part of the pre amp after doing a 2
way split? I have a power passive splitter. reason Im asking is
because after the split a HDTV will be right next to it, and Im
going to have to run 70 feet of more coax for the 2nd Tv and that's
where I want to power up the amp.

I would have said the Winegard UT-2700 UHF Signal Trap, but its price has skyrocketed. Besides you then need to find a way to tune it, which can be difficult without proper test equipment. You may be better off getting a Tinlee Notch Trap as they will tune it for you.

Keep in mind that after the analog shutdown you may not need it anymore.
Why might I not need a notch filter after the 2011 analog shut down? Are digital signals less susceptible to overolad tuners- even if one is very close to the transmitter and the signal is very strong?

Why might I not need a notch filter after the 2011 analog shut down? Are digital signals less susceptible to overolad tuners- even if one is very close to the transmitter and the signal is very strong?

DTV transmitters on the same channel tend to need 1/10th (10 dB less) power of analog to get the same coverage so the interfering signal(s) will likely be significantly weaker. The exact amount of power is under some debate though, but that is a topic for a different thread.

Is it Ok if I attach the power part of the pre amp after doing a 2 way split? I have a power passive splitterYep, as long as the power pass capability applies to that line between the preamp head and its power injector.

RF Splitters marked for SATELLITE nearly always have DC PASS on one or both ports.

Just be careful. If the splitter has power pass on both sides the DC power could damage equipment connected to the other port. Regardless it would be safest to put a DC Block on the side you don't want power passed.

Just be careful. If the splitter has power pass on both sides the DC power could damage equipment connected to the other port. Regardless it would be safest to put a DC Block on the side you don't want power passed.
Or simply use a VOM to see if the TV connected to the second port presents a low resistance load (unlikely, but just in case).
Perhaps there is a SAT Receiver out there that provides DC power on the OTA Coax port???? Or you inadvertently connect
the OTA coax to one of the SAT ports (which do provide DC power).

Or simply use a VOM to see if the TV connected to the second port presents a low resistance load (unlikely, but just in case).

This test won't tell you much. Various components could provide a high resistive load, but still fry when 18VDC is applied.

Perhaps there is a SAT Receiver out there that provides DC power on the OTA Coax port???? Or you inadvertently connect
the OTA coax to one of the SAT ports (which do provide DC power).

I assume these are arguments as to why equipment would be designed to tollerate DC power? Just because they should be designed that way doesn't mean it is. Generally the rule is if you connect something up incorrectly it may cause damage.

This test won't tell you much. Various components could provide a high resistive load, but still fry when 18VDC is applied.
You must live in an some alternative universe where VOM's don't use DC Voltage to measure resistance.....

You must live in an some alternative universe where VOM's don't use DC Voltage to measure resistance.....
They do, but usually less than 9V, and frequently *a lot* less than 9V.

If the input to the TV goes directly into a pre-amp transistor without a DC-block cap, for example, it'll fry at anything over 5V or so.

Cheers

If memory serves me (it sometimes does), an ohmmeter uses a constant current source (specific amount for each range), then measures the voltage developed across the device under test to determine the "resistance" of the device.

I have a pair of digital multimeters here. According to those (one measuring the other), the voltage varies by ohms-range setting, from a fraction of a volt up to about 2.6V.

The current also varied.

I suspect various methods and voltages are used, depending upon the model/maker.

-ml

thanks the splitter has dc power passive on both sides. is it still
ok to use the splitter inbetween the pre amp and power supply.

thanks the splitter has dc power passive on both sides. is it still
ok to use the splitter inbetween the pre amp and power supply.
NO!
you need a splitter that passes power on one side only.
Save and Replay sells them.
So does Home Depot.
(the point that got burried in the last 10 posts was that you don't want to send the DC to another tv)
(i'm also pretty sure there would be a proper place for arguments about multimeters, but this isn't it.)

Just be careful. If the splitter has power pass on both sides the DC power could damage equipment connected to the other port. Regardless it would be safest to put a DC Block on the side you don't want power passed. the point that got burried in the last 10 posts was that you don't want to send the DC to another tvAll clear, ontherooftop? Use a splitter with DC Power Pass on only one side. :)

They do, but usually less than 9V, and frequently *a lot* less than 9V.

If the input to the TV goes directly into a pre-amp transistor without a DC-block cap, for example, it'll fry at anything over 5V or so.

Cheers
Static electricity buildup on ungrounded (and even some grounded) antennas can easily exceed 5 VDC....ZAP!!!
And using a VOM to check for shorts in the coax connectors is fairly common....
Hence these defective designs wouldn't last in the market place very long before they hired a new engineer....

Other than the apparently intentional DC Short in C-M Baluns....and a couple defective RF Splitters I've seen,
I don't think there ARE that many "DC short circuits" to worry about.....

Ok so is it better then to put the pre amp power on first and then
do the split after? because the splitter is going to cause a 3.7db loss
and also I would have to run a 70 foot cable to a second TV which
is another 3.5db loss. Am I missing something here? The pre amp
is 19db for UHF winegaurd. Would the 19db compensate for the 7.2
db loss to the second TV even if I use the splitter after the power
source? also there will be runs from the antenna to make that 19db
into use.

Ok so is it better then to put the pre amp power on first and then
do the split after? because the splitter is going to cause a 3.7db loss
and also I would have to run a 70 foot cable to a second TV which
is another 3.5db loss. Am I missing something here? The pre amp
is 19db for UHF winegaurd. Would the 19db compensate for the 7.2
db loss to the second TV even if I use the splitter after the power
source? also there will be runs from the antenna to make that 19db
into use.
NO, it is better to use a splitter that has power pass on one side only. as was said already.

Thanks Tom, But will both Tv's benefit from this?