[imaki]

Hi All! I need some help.


I am installing a CM4228 for OTA digital through a terk BMS58 multiswitch to my receiver (t160) and am having some issues.


The full setup is:


D* phase III dish -> Multiswitch (4 Sat inputs)

CM4228 -> CM 3401DBS amp -> amp power -> Multiswitch (OTA input)


at the receiver end I have a RCA diplexer which breaks out the antenna and satellite signals.


When OTA is not through the switch everything is fine. When through the switch I have no signal. I have tried DC blocks on each end (antenna & reciever), removed the amp, and even bought a terk diplexer to see if terk didn't work well with RCA, but no luck. When I diplex (can that be a verb?) at the antenna end and don't go through the multiswitch I get a signal, but any time I go through the switch there is no more signal.


Here are the combinations I have tried:

• CM4228 -> CM 3401DBS amp -> amp power -> Multiswitch (OTA input) -> diplexer -> receiver (no signal)
• CM4228 -> Multiswitch (OTA input) -> diplexer -> receiver (no signal)
• CM4228 -> Multiswitch (OTA input) -> dc block -> diplexer -> dc block -> receiver (no signal)
• CM4228 -> CM 3401DBS amp -> amp power -> dc block -> Multiswitch (OTA input) -> diplexer -> dc block -> receiver (no signal)
• CM4228 -> CM 3401DBS amp -> amp power -> diplexer -> diplexer -> receiver (sat and OTA are great)

All I can think of is that I got a defective multiswitch. I can get a replacement, but I wanted to see if any of you gurus out there had any other recommendations.


Thanks for your time!


Ian Maki

 

[greywolf]

The BMS-58 passes its 24VDC power out the antenna input to power a preamp. Try CM4228 -> CM 3401DBS amp -> Multiswitch (OTA input). Check that all connectors are tight on the cable. Check for cable continuity and shorts.


EDIT-Reports indicate that the BMS-58 spec sheet is erroneous. It does not pass 24VDC out its antenna connection.-EDIT

 

[imaki]

Thanks for the quick reply greywolf!


I did try bypassing the amps power, but that didn't work either. I thought it might cause an issue since the amp wants 18VDC for power, but it seemed fine when I used the CM power again.


I tried multiple cable combinations from the antenna to the switch, but nothing worked. I tried the same cables that are currently working using the diplexer instead of the switch.


How would I test for shorts?


Thanks again!


Ian

 

[greywolf]

If the cables work by replacing the multiswitch with a barrel connector, they are ok. You may indeed have a rare bad multiswitch.


If your amp wants 18VDC instead of the usual 24VDC though, CM4228 -> CM 3401DBS amp -> amp power -> dc block -> Multiswitch (OTA input) -> diplexer -> receiver is the way to go. You'll need to block the excessive DC from the multiswitch from getting to the amp. Never put a DC block in the lines between the receiver and the dish that handle satellite signals. The receiver sends 13VDC to select odd numbered transponders and 18VDC to select even numbered transponders on the dish LNBs.

 

[imaki]

Thanks greywolf.... I will try the dc block between the switch and amp power tomorrow when I have some light to go by.


Ian

 

[imaki]

No luck with the DC blocker between the switch and the amp power. I sent the switch off for replacement today.


Thanks again greywolf!


Ian