Hi, is Stridsberg still in business and repairing MCA104's? Mine is deaf.
It doesn't look like they have updated their web pages since 2013.
Thanks, G
Yes, they are in business.
The website has been updated with newer models of several products recently but John may have missed updating the sites date that is displayed.
I own several of their products and they are built very well.
When I had problems, they always repaired them for free even if caused by myself from accidently transmitting through their preamps or multicouplers.
John even sent me spare RF transistors for free so I could repair them myself so I was not wasting his time fixing my mistakes.
He even made me custom preamps with less gain than his production models.
edit: Common problems I've caused with the MCA104 is blowing the RF amp by accidently transmitting back through the multicoupler. They do not fare well if you do that even with just a watt or two.
In one or more cases, when I took out the RF amp, it also took out the 8 VDC regulator he uses in many of his products.
The RF amp can be purchased from Mouser or Digi-Key and the 8 volt regulator can also be obtained from Mouser or Digikey
They also contain some resistors used for setting the bias and also tuning the freq range of the coupler as well as some SMD capacitors of which I forget the value of now.
Some of the caps are used to set the freq range and some are simply there for filtering.
The MCA104M should be capable of being powered over the coax as well as using a wall wart of 12 VDC plugged into the 104's power jack.
They only draw a very small amount of current so a 12VDC wall wart with just 100mA current rating will power the 104M with no problem.
I power all my Stridsberg amps and couplers from a common battery backed up power distribution system I custom built that also powers my many radios so I can keep my station running for hours or even days if I lose utility power.
Some of my older Stridsberg preamps only draw about 10mA and I think most of my 8 port couplers may only draw about 50mA.
Send John an email and he will often tell you what part number you need if you want to repair the unit yourself or he will offer to sell or even give you the parts needed. You just need to be skilled in working with SMD mounted components. If you want it done right, send the 104 to John and he will replace the bad part(s) and make sure the correct frequency range is maintained. Too much solder on some of the stripline boards he uses can alter the frequency range of the RF amp for example.
The RF splitters he uses do not often fail even if you accidently transmitted through the unit. The splitters are usually made by Mini-Circuits and are pretty robust. I've never had an internal splitter fail.
Also as has been mentioned in this thread is failure from nearby lightning strikes.
That will take out the RF amp and sometimes the regulator.
I once accidently stacked two preamps in front of a multicoupler and that produced too much input at the multicoupler which toasted the RF amp.
The 2nd preamp handled the high RF levels from the 1st preamp without toasting it also.
