Televes power units for masthead amplifiers - why 2 outputs only?

Antenna

Televes masthead amplifier powersupply units - why are these manufactured as 2 outputs units only? Bizarrely they seem to have no model with one output?? Why??
http://www.televes.com/fotos/8203.jpg
If viewers want a split - this will often be done with the RF out of something with a modulator - such as a VCR or satellite receiver - meaning one of the two output ports on these masthead amplifier PSUs is usually left unused. This represents unnecessary signal loss (there is still going to be a loss if only one of the 2 outputs of the masthead PSU is used) - which could easily impact for example unamplified VHF Band 3 (diplexed with amplified UHF) on the downlead (a common scenario in areas where RTE 1/2 are on VHF)

http://www.televes.com/hojastecnicas/103838.pdf

byte

Seems odd alright. I generally avoid double output PSU's due to loss, as there are areas here that just are on edge signal wise, and losing a few precious dB is not on!

I generally use Triax PSU's and masthead amps, though I've found their masthead amps to be less reliable more recently. Their PSU's seem OK though (I just hate the new trend of having to use connectors for PSU's unlike good ol days of screws and braid clamp)!

Rippy

i agree double output psu s are a pain. Unfortunately my most common m/h amp (Wolsey /Triax WFAV25 ) comes packaged with one. it's a pity because otherwise it is an excellent amp (well screened , low noise figure, adjustable), the psu is good too , but why a fecking twin output?
I just use a triax P100 single psus where the loss on the split is going to present a problem.
Oh yeah ,I actually prefer connectors on amps and psu's to saddle and clamp, as long as they are f conns. Better screening and quicker (with a cable stripper and crimping tool.)

stylers

good old fringe still have the old screw clamps PSU's, one output of course..

byte

Thanks for that, might check them out. Not a fan of their masthead amps though.

Antenna

I had one of these 2-output Televes Power Units (the 8203: 2 output, 12V 100mA max to amp) - but wanted to modify it to one output only for minimal loss!
(other single output power units I had didn't have good RF screening)

Firstly I opened up the unit - see the first of the three attached pictures for what is inside

It wasn't too difficult to prize off the cover of the screened RF section - a resistive splitter with two 39 Ohm resistors is to be found inside (second picture).

I then removed the resistors and used a link to modify it for use with one output only - see last picture. The cover pops back on


incidentally - in the first picture for those interested - the large electrolytic capacitor after the bridge rectifier is 1000uF, the regulator is a LM78M12CV (i.e. +12volts output) , the small electrolytic capacitor on its output is 3.3uF

watty

I've found "proception" the best.

Sealed units with F-Connectors.

netwhizkid

watty wrote: »

I've found "proception" the best.

Sealed units with F-Connectors.

I used one of these recently in conjunction with a Triax Masthead amp and it works great from Mullaghanish.