Hi,
The GNA/TNA have an internal 3-way combiner on ALL versons. The manufacturer recommendation depends on what type version you have and with what type of return amplifier is installed...4-LER or 5-LER.
First of all, there is an internal loss from KS-port to return hybrid of 7dB that includes the diplex filter and any other circuitry. If you are injecting directly into the "jumpered" pad location (found only on the 750MHz SMCR versions) this will yield only a 5dB loss from that point to the return hybrid. As you probebly already know, you are not able to inject into the forward output testpoint on the "B" and "D" versions as it is common to the high side of the diplex filter.
My suggestion, as others have stated, it inject into an external tap and vary the tap value to allow sufficient level to your hybrid. I have seen customers use anywhere from 15dBvM to 18dBmV input at that point.
I actually worked in Gulfport and Saucier prior to Katrina and was in Pascagoula until mid-2006. If you have any further Magnavox questions, feel free to call and ask. I was a field engineer with Philips Broadband/Magnavox for years and still try to work with old customers as a need for support still exists.
Good luck!
Greg Tobin
Interactive Broadband Technical Services
314-422-4423 cel
http://www.interactive-broadband.com
Re: magnavox amps...grinder143
Member #: 7190
Registered: 1996-2001
Posted:
483
Name:
Greg Tobin
Name:
Greg Tobin
Company:
Interactive Broadband Technical Services
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HFC Engineer/Consultant
Location:
www.interactive-broadband.com
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~45 years
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