> Jeff, out of all the PAs you've seen out there, both commonly
> used and not-so-common... which ones (in your opinion) are
> properly designed (when "working right")?
I think a lot of them, generally speaking, are properly designed. That's
not to say that some of them don't have some downsides or specific,
recurring points of failure (to wit: the beloved Mastr II output strap
connection failure). I'd name manufacturers that are on my $^!+ list, but
I'd rather not do that here, but I will say that most of them are the
made-for-amateur brands. I've had great luck with just about anything Micor
(and, I have to say, significantly better long-term results with Micor over
M2, sorry GE fans). Crescend and *newer* TPL amps have been good to me.
EFJ CR1010 PA's have also been workhorses.
> I have this feeling that most, if not all, have various
> problems... but you've seen a heck of a lot more of them
> in-service than I have.
Well, I dunno, there are probably others on this list in the two-way
business that have seen more than me. I do broadcast for a living; I'm
generally an RF guy, my interest in repeaters is just a subset of that. I
have a bunch of ham repeaters (20-some I think), and maintain a bunch for
other individuals/clubs, and have built or maintained many for others over
the years, but I'm sure there are others that do two-way on a daily basis
that can give more points of reference as far as recurring problems with
other brands/models that I'm not as familiar with.
> I ask, because this is always the kind of mature,
> well-developed tech I'm looking for. Price is still a factor,
> but when you find something that "just works"... it's truly
> grand in the tech world, for all sorts of reasons that tend
> to degrade what something was intended to be, vs. what it
> really ended up being.
To me, the cost of the radio hardware is the least of my worries. I'm not
saying that to sound like an alpha-hotel. I look at it this way. I've got
all of these repeaters to deal with. I have no free time the way it is.
When one breaks, that means I have to take a day off work (or away from
family, or away from something else) to go deal with it. It probably means
a few hundred miles of driving. And, more than likely, if it's a major
failure, I'm probably going to have to make a return trip, doubling the
time/cost. So do I really want to take a chance on low-grade hardware up
front? No way.
Whoever said "time is money" was an idiot. Time is worth inifinitely times
more than money. You can make more money. You can even borrow money.
Hell, if you were desparate you could even steal money. You can't do any of
those things with time. Time is the one resource you can't make more of.
And, for me, I've never had enough time to get everything done that I want
to get done. Life's too short to waste time on high-maintenance equipment.
> I'm also curious to see if your recommendations are new gear,
> or 20+ year old gear.
Both. While I still believe the glory days of two-way turned out the best
damned equipment ever made, there is still some decent stuff being made
today.
> I really like MASTR II Stations, but I will admit to some
> consternation over how the PAs *sometimes* act. We've had 'em
> run for a decade, and we've had 'em pop like light bulbs
> every few months.
With the exception of the PA's, they generally just run. 100 watt UHF M2
PA's have been rather disappointing for me, both with and without matching
networks, with or without isolators. 75 watters seem to run forever.
Highband and lowband, much fewer problems. I have a bunch of the 200 watt
solid state M2 stations, and have pulled them all out (except for one, which
is coming out in a week or two), they're just a nightmare to keep all three
PA's working all the time.
> Is the answer to this question the Crescend amps perhaps?
I've been happy with them. I have 7 or 8 of the previous-vintage UHF
Crescend/Milcoms (the gold-alodined ones that you're probably familiar with)
on the air, and they've been fine, running in the 150-175 watt range. I
ordered a couple 100 watt highband amps for a local club about a year ago,
they seem OK. I have a bunch of their 900 MHz linear amps in use on STL's
and they've been solid. I wouldn't hesitate to buy them.
> How
> did their acquisition of Vocom affect their quality?
They did change their design, and talking to their engineers a few months
ago, they're doing some re-designs due to some of the devices they had been
using going on EOL, so more changes will be forthcoming.
Some of the older pre-Crescend Vocom amps weren't very good.
> I
> haven't looked lately, did they mix up the model line and
> keep the Vocom stuff?
They still have the Vocom line which they market as a lower-cost
alternative.
I like the TPL RXR series because they are extremely simple. They also have
one device per board, so in the event that you have a device fail or burn up
a collector trace or something, you only have one board to replace.
Splitting and combining is just simple Wilkinsons. Devices are, for the
most part, good old Motorola MRF series (at least for now, until they run
out). They use the same PCB for all stages, just different devices and
different values for the metal-clad mica caps. All very simple. Simple is
good.
By the way, somewhat on-topic, I had a couple of TE Systems amps that I had
been procrastinating on sending back to TE becuase I had rather bad
experiences with their repair/customer support in the past. These two amps
were on commercial frequencies (463 MHz, 175 watt and 157 MHz, 350 watt), so
they both needed a lot of caps replaced for retuning to the ham bands, more
time/aggrevation than I was willing to invest myself. I sent them both in a
couple of weeks ago. I'll report back how my experience goes this time...
--- Jeff WN3A
