View Single Post
Old 8-Jul-2016, 2:26 AM   #19
Retired A/V Tech
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,736
I have a Question, about the mast mount amplifier, I have it has one VHF in at 30B,& UHF in at:40B, should I use it full power?
Uh-Oh, you changed amplifiers on me.

This thread has the title:
HD 8200u is it to MUCH with a channel master 7777amp

So I made my calculations based on the CM 30 dB 7777 amplifier for UHF and VHF combined, to answer that question.

40 dB is TOO MUCH.

More is not better, it will cause overload.

You only need 18 to 24 dB to make up for distribution losses.

Channel Master on their page for the 7777 says be careful with the 30 dB 7777.

Are you talking about the Johansson 7404?

Do you have a Johannson 7404 or are you going to buy one?

Please notice in attachment 4 that the 2430 power supply requires 230V AC, not 120V AC.
Attached Images
File Type: jpg Johannson snip1.JPG (146.5 KB, 489 views)
File Type: jpg Johannson snip2.JPG (74.1 KB, 509 views)
File Type: jpg Johannson snip3.JPG (62.8 KB, 495 views)
File Type: jpg Johannson snip4.JPG (59.2 KB, 482 views)
Attached Files
File Type: pdf Johansson REF.7404 .pdf (97.0 KB, 475 views)
If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 8-Jul-2016 at 2:58 PM.
rabbit73 is offline   Reply With Quote