Does anyone know what the published specs are for the Winegard SD-3300 combiner? Just curious...I am using one to eliminate two baluns and a combiner and hopefully gain some signal.

Ok what are the loss numbers for the sd3700? I have an XG91 & unknown VHF antenna to combine.

Wow, pretty impressive loss numbers...but to use that I would have to use two baluns and they have some loss...wouldn't it be better to use a model that accepts 300 ohm inputs and has 75 ohm output.

I would still like to know where I can find the specs for the sd3300 or sd3700.

The 91XG does use a balun/matching transformer. It might say a printed circuit board transformer, but if you open the matching box it is only a common balun. My VHF reception is ok as is. The preamp is: winegard 8780 (17db VHF NF 2.9, 28db UHF NF 2.7)

Thanks for the info Rick0725...I just ordered the cm0549...since I installed the SD-3300 my UHF reception has dropped which supports what you said about it having high db loss...I do need to install RG-11...it is expensive...I saw the Commscope RG-11 in the link you provided but saw that the center conductor is copper-coated-steel and not bare copper...I thought I saw in the forum somewhere that CCS was not good and to look for BC (bare copper)?

Ah, but the Winegard CS-7750 VHF/UHF Separator/Coupler has .3 db insertion loss! And is a nice blue color that matches my blue colored BlueJeans coax (Belden 1694, Canare connector) cable. My system is color co-ordinated.

install my 3 new kitzteck 1 db noise amps

Rick, I'm curious. How are you going to use the Kitztech? My antenna is in the attic and I have a power outlet in the attic. So I can power my Kitztech there. Aren't your antennas outside? How are you going to power the Kitztech outdoors? Its power module doesn't connect to the preamp via coax.

The CS-7750 looks like it is meant for indoor use? Also can someone enlighten me as to the difference between Belden 1523A, 1523AP & 1523R?

Ok, I installed the cm0549 to combine my XG91 & VHF antennas...also upgraded to RG11 (240' run)...signal strength is MUCH improved!...I can now receive digital from ~85 miles during the day with no pixelation...before I could not receive those stations at all during the day...many thanks to all of you!! I have learned much!

Published, decimal insertion loss values of virtually identical passive components are meaningless for the purpose of selecting one over another. The loss varies depending on the frequency, and the loss will vary with the exactness with which the actual impedance of the load formed by the passive device and the load components matches the exact real impedance of the source device.

Why does Jesse31 think that reducing the insertion loss by a couple tenths of a dB is important in his situation?

I was referring to the comparisons of published insertion loss figures of 0.3, 0.4 and 0.5 dB for passive baluns and combiners. I once took a couple of baluns that had a published insertion loss figure of 1 dB and connected them back to back, and the combined insertion losses varied from less than 0.5 to as much as 4dB at different UHF frequencies. Other comparable baluns will fluctuate similarly, but peaking and cresting at differnt frequencies.

AntAltMike...have you read the entire thread?..I was combining the antennas with a sd-3300 and switched to a cm0549 and you are saying that I reduced the insertion loss by only a couple tenths of a dB?

AntAltMike...have you read the entire thread?..I was combining the antennas with a sd-3300 and switched to a cm0549 and you are saying that I reduced the insertion loss by only a couple tenths of a dB?

Having read a number of these threads on power splitters and seeing your question confirms my suspicion that there is a lot of confusion here.

Nowhere in this thread did anyone say you started with a power splitter and went to a diplexer. These are two different animals.

A power splitter is fine for combining two identical antennas (stacking) but is not fine for combining two different antennas, like VHF and UHF. That's the job of a diplexer.

A 3 dB power splitter is simply a broadband impedance transformer that goes from 75 ohms to 37.5 ohms. Two 75 ohm loads in parallel is 37.5 ohms which is the impedance of two identical antennas connected together. When used as a splitter the minimum loss is 3 dB - half the power goes to each port. Anything above 3 dB are inefficiencies in the circuit and I would refer to as Insertion Loss. If each port measured -3.5 dB, then the total gain of two antennas would be 2.5 dB, not the theoretical 3 dB.

If one company says their splitter is 3.5 dB loss and a second says theirs is 0.5 dB loss, it's very likely that they're exactly the same. The second assumes that you know that 3 dB is the definition of splitting the power in two.

A diplexer is a device with two bandpass filters in it (or maybe a low pass and a high pass filter). In our case with separate VHF and UHF antennas, one filter needs to pass from 54 to 216 MHz with low loss and the other from 470 to 800 MHz with low loss. There's no impedance transformation necessary since the antennas never appear to be in parallel at the same frequency. There is no power splitting loss, only insertion loss. Good isolation between ports prevents one antenna from affecting the other.

In your case you picked up 3 dB going from a splitter to a diplexer to combine different antennas (assuming equal losses in each device) and you reduced the potential for one antenna interfering with the other due to lack of isolation. You also picked up about 3.5 dB at channel 60 with 240' of cable by switching from RG-6 to RG-11.

I hope this make some sense.

Why does Jesse31 think that reducing the insertion loss by a couple tenths of a dB is important in his situation?

So AntAltMike thinks that the difference between the SD-3300 and the CM-0549 is only a couple tenths of a dB?? Wrong.

The Winegard SD-3300 I was using is meant to be used for combining identical antennas...it had a large loss...when I switched to the cm0549 my signal picked up a great amount...The cm0549 was a better choice and apparently has much less loss...after switching to RG11 signal improved greatly again. AntAltMike's comment was offbase and it was apparent that he had not read the entire thread....The bottom line is I have a terrific signal now thanks to some knowledgeable helpful people....and as Mr. Gump said: "Thats all I have to say about that."