SnowDog51's profile

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Tuesday, September 23rd, 2025

Correct amp for XB8 2 Gb service?

I am asking what is the correct amp to use with xFinity 2GB service?  I am suppose to get 300mb uplink but struggle to get 70.  I think it is because my current amp is a  Commscope CSMAPDU9VPI.  I think it should be CSMF1APDU9VPI?  That amp will use the 5-85 Mhz band where the one I currently have only goes 5-42Mhz.  Is this correct or what should I be using?  Thanks,

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111 Messages

2 days ago

Question for you: Did an Xfinity technician test your entire setup and determine that you actually needed an amp? If not, I’d recommend you remove the amp entirely, consolidate any connections needing splitters, and remove every possible source of signal loss in your setup, that you can do without. Your modem really needs to have zero splitters, amps, barrel connectors, etc., and the absolute minimum number of connectors in general, between it and the Xfinity box on the side of your house. Then have an Xfinity technician check your entire setup. Tweak as needed per the professional assessment. 

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13 Messages

@user_323c89​   It's a large home.  There are 8 lines coming from the amp to serve various points in the house.  I am currently getting 2.1 GB down but only 70 mb up.  should be 300.  xFinity gave me a new XB8 modem but did not mention I would need to change the distribution amp.

Do you or anyone know where I can purchase a CSMF1APDU9VPI amp?  Having trouble finding one.

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13 Messages

2 days ago

Does anyone know where I can purchase a Commscope CSMF1APDU9VPI amp?

Thanks.

Expert

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113.5K Messages

2 days ago

@SnowDog51 

Neither one of those amps can be used in mid-split systems as they both have 5-42 MHz returns. The only difference in the second one is that the forward path extends up to MoCA frequencies (1125-1625 MHz). 

As was stated, try to avoid using any drop amps at all ! If you really need one, you need one that has a 5-85 Mhz return as you stated;

https://www.antronix.com/products/residential-amplifiers/midsplits 

(edited)

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I think the Commscope CSMF1APDU9VPI does handle the split as it is specified as 5-85 MHz and 102-1002 MHz with MoCA at 1125-1675 Mhz.  I think this is very close to the Antronix MVRAM901B-G2 that you referenced?  Am I missing something? Thanks.

Expert

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113.5K Messages

2 days ago

@SnowDog51 

I'm not the manufacturer. If you zoom in on the picture, it says "5-42 MHz (Rev)" return path on it. Perhaps someone with more knowledge / authority will chime in here. Good luck

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That's a problem with some of the listings.  The picture is not correct.  If you zoom on the picture's part number it is wrong.  If you pull the spec from Commscope - it will have the correct split band info.  I don't see how to upload anything here or would post the info.  I will try to copy some info.  Let me know if you think this will work.  Thanks.

CSMF1APDU9VPI:

Passive VoIP MoCA Amplifier, unity forward/reverse, 85 MHz return, nine
ports, with power inserter
Product Classification
Brand HomeConnect®
Product Type RF amplifier


Environmental Specifications
Operating Temperature -40 °C to +60 °C (-40 °F to +140 °F)
Safety Standard SCTE


Electrical Specifications Rx (Uplink)
Operating Frequency Band 5 – 85 MHz
Insertion Loss, video ports 0.00 dB
Flatness ±1.0 dB
Return Loss, minimum 20.00 dB
Noise Figure, maximum 18.00 dB


Electrical Specifications Tx (Downlink)
Operating Frequency Band 102 – 1002 MHz
Gain, video ports 0.00 dB
Flatness ±1.0 dB
Return Loss, minimum 20.00 dB
Noise Figure, maximum 10.50 dB


Electrical Specifications VoIP
Insertion Loss Rx at Frequency Band, VoIP ports, maximum 4.3 dB @ 5–42 MHz
Insertion Loss Tx at Frequency Band, VoIP ports, maximum 4.5 dB @ 54–550 MHz | 6.0 dB @ 550-1002 MHz
Return Loss at Frequency Band, VoIP ports, minimum 20 dB @ 5–1002 MHz


Electrical Specifications MoCA
Operating Frequency Band 1125 – 1675 MHz
Band Rejection, output to input, minimum 40.00 dB
Band Rejection, VOIP to input, minimum 35.00 dB
Insertion Loss, output to output, maximum 35.00 dB
Insertion Loss, output to VOIP, maximum 35.00 dB
Insertion Loss, VOIP to output, maximum 35.00 dB
CSMF1APDU9VPI
page 1 of 3
January 29, 2019
©2019 CommScope, Inc. All rights reserved. All trademarks identified by ® or ™ are registered trademarks,


respectively, of CommScope.All specifications are subject to change without notice. See www.commscope.com for the
most current information. Revised: December 19, 2018


Electrical Specifications Isolation
Isolation at Frequency Band, output to output, minimum 25 dB @ 5–1002 MHz
Isolation at Frequency Band, output to VoIP, minimum 25 dB @ 5–1002 MHz
Isolation at Frequency Band, VoIP to output, minimum 25 dB @ 5–1002 MHz
Isolation at Frequency Band, power port to RF output, minimum 60 dB @ 5–1002 MHz


Electrical Specifications
Group Delay, 2nd channel, maximum 30 ns
Group Delay, channel 3, maximum 15 ns
Group Delay, channel 4–6, maximum 5 ns
Impedance 75 ohm
Operating Current at Voltage 380 mA @ 15 Vdc
Distortion Performance (CTB), minimum 73 -dBc
Distortion Performance (CSO), minimum 65 -dBc
Distortion Performance (X-Mod), minimum 73 -dB
Distortion Performance (CCN), minimum 60 -dBc
Distortion Performance (DTO), minimum 60 -dBc
Distortion Performance (DSO), minimum 55 -dBc
Hum Modulation, minimum -75.00 dB
Group Delay, reverse, maximum 25 ns
Shielding Effectiveness, minimum 100 dB
Surge Capability Test Method ANSI/SCTE 81 | IEEE C62.41-B3 (6 kV, 3000 A, Combination
wave) on all ports
Surge Capability Waveform 1.2/50 voltage and 8/20 current combination waveform | 100
KHz ring wave waveform


General Specifications
Device Type All ports down amplifier | Two-way subscriber
amplifier | VoIP subscriber amplifier
Video Ports, quantity 8
VoIP Passive Ports, quantity 1
Application Indoor | Outdoor
Includes Power adapter | Power inserter
Video Standard NTSC
Patent Number 7912431 (expires 8/2/2025)


Packed Dimensions
Carton Quantity 20
Height 190.50 mm | 7.50 in
CSMF1APDU9VPI
page 2 of 3
January 29, 2019
©2019 CommScope, Inc. All rights reserved. All trademarks identified by ® or ™ are registered trademarks,
respectively, of CommScope.All specifications are subject to change without notice. See www.commscope.com for the
most current information. Revised: December 19, 2018
Regulatory Compliance/Certifications
* Footnotes
Length 508.00 mm | 20.00 in
Width 247.65 mm | 9.75 in
Shipping Weight 9.07 kg | 20.00 lb

Expert

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113.5K Messages

2 days ago

Perhaps the pic is wrong. One or the other is. The specs do indeed say "Operating Frequency Band 5 – 85 MHz". But why not go with the sure thing (the Antronix) ? No amp at all is usually best and is recommended by cable techs and industry experts alike ! Are your signal values in spec / have ample wiggle room ? A passive splitter(s) that supports mid-split may be preferable

(edited)

Expert

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113.5K Messages

1 day ago

@SnowDog51 

FWIW, finally found a pic that clearly shows F1apdu9vpI, 5-85 Rev on the label;

https://catalog.optech.net/avcat/ctl19093/index.cfm?manufacturer=commscope&product=csmf1apdu9vpi 

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13 Messages

How do I purchase the CSMF1APDU9VPI??  Can't find it.

Expert

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113.5K Messages

13 hours ago

Either can I, sorry. If a Comcast tech confirms that you need one, they may be able to provide and install one at no cost. Good luck !

Official Employee

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2.6K Messages

12 hours ago

 

SnowDog51 Have you had a technician out recently to check on your speed concern? 

 

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13 Messages

It is extremely difficult to get a tech scheduled.  You have to go through many many hoops online or on the phone.  You either get in a do loop or disconnected.  I have given up and trying to get the amp that I need myself.

Official Employee

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579 Messages

We would be more than happy to work with you to schedule a technician if need be. I would just need some additional information from you. 

Please send us a direct chat message with your full name and complete service address to “Xfinity Support”. To do so, click on the chat icon located at the top right of this forums page.

 

To send a "Direct Message" to Xfinity Support:

 

Click "Sign In" if necessary

Click the "Direct Messaging" icon or  https://forums.xfinity.com/direct-messaging

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Type your message in the text area near the bottom of the window and press Enter to send it.

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