Why are they so expensive? I've put off buying some for my Collins rig
because of the price.


--

Regards
B.H.

Brian's Basement
http://webpages.charter.net/brianhill/6.htm

Brian's Radio Universe
http://webpages.charter.net/brianhill/500.htm

Cuz they're in demand and no longer made. Pretty simple, really.

"Brian Hill" wrote in message
...
Why are they so expensive? I've put off buying some for my Collins rig
because of the price.


--

Regards
B.H.

Brian's Basement
http://webpages.charter.net/brianhill/6.htm

Brian's Radio Universe
http://webpages.charter.net/brianhill/500.htm

"Old Guy" wrote in message
news:1130290220.c4efe347713261456df1beb6517134be@m eganetnews2...
Cuz they're in demand and no longer made. Pretty simple, really.



They are still being made.

"Old Guy" ) writes:
Cuz they're in demand and no longer made. Pretty simple, really.

There was a review of a recent line of Rockwell/Collins mechanical
filters somewhere in the last years of "Communications Quarterly" so
I suspect they are still being made.

Collins mechanical filters were always costly. Surely some of it
is because they aren't simple to manufacture. They also supply
good performance. They were never a mass item, so there was nothing
to drive cost down as demand went up.

Note that commercially made crystal filters also carry a relatively
high price tag.

Michael VE2BVW

"Brian Hill" wrote in message
...
Why are they so expensive? I've put off buying some for my Collins rig
because of the price.


--

Regards
B.H.

Brian's Basement
http://webpages.charter.net/brianhill/6.htm

Brian's Radio Universe
http://webpages.charter.net/brianhill/500.htm

Behold, Michael Black scribed on tube chassis:


Collins mechanical filters were always costly. Surely some of it
is because they aren't simple to manufacture.

Heh, where's the overseas knockoffs?

--
Gregg "t3h g33k"
http://geek.scorpiorising.ca
*Ratings are for transistors, tubes have guidelines*

Gregg wrote:

Behold, Michael Black scribed on tube chassis:

Collins mechanical filters were always costly. Surely some of it
is because they aren't simple to manufacture.

Heh, where's the overseas knockoffs?

--
Gregg "t3h g33k"
http://geek.scorpiorising.ca
*Ratings are for transistors, tubes have guidelines*


Lafayette Radio used to sell them, but they are long gone. There
wasn't enough of a market for the knock offs, either.

--
?

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote in message
...
Gregg wrote:

Lafayette Radio used to sell them, but they are long gone. There
wasn't enough of a market for the knock offs, either.

--
?

Michael A. Terrell
Central Florida

Collins got on them regarding patent infringement issues.

Pete

"Michael A. Terrell" ) writes:
Gregg wrote:

Behold, Michael Black scribed on tube chassis:

Collins mechanical filters were always costly. Surely some of it
is because they aren't simple to manufacture.

Heh, where's the overseas knockoffs?

--
Gregg "t3h g33k"
http://geek.scorpiorising.ca
*Ratings are for transistors, tubes have guidelines*


Lafayette Radio used to sell them, but they are long gone. There
wasn't enough of a market for the knock offs, either.

And of course, for a lot of things ceramic filters filled the need
for a filter better than a string of IF transformers (or a single crystal
in a phasing arrangement), but at low cost. You see them in most cheap
am/fm radios now, where their size and cost is likely why they are
used, through shortwave receivers costing hundreds of dollars, to even
ham transceivers (though in that instance they tend to be used in
conjunction with some sort of better filter). And the ceramic filters
do cover a lot of territory, going from those three terminal ones we
see in the average am/fm radio, to multiple pole filters seen in those
more expensive bits of equipment.

Michael VE2BVW

Gregg ) writes:
Behold, Michael Black scribed on tube chassis:


Collins mechanical filters were always costly. Surely some of it
is because they aren't simple to manufacture.

Heh, where's the overseas knockoffs?


Well there were other manufacturers who made mechanical filters in
the sixties. You'd see them in the Lafayette catalog, and mentioned
in reviews (though I've always wondered if some of those reviews got
it wrong, and they weren't mechanical filters). But they were never
commmon. They were cheaper than Collins filters, but I have no idea how
absolutely cheap they were for the time. I don't recall coming across
real specs in the old magazines, either. I also recall in recent years
that it was those other filters that used foam rubber inside, and by
now much of that has deteriorated.

Michael VE2BVW

"Michael Black" wrote in message
...

Well there were other manufacturers who made mechanical filters in
the sixties. You'd see them in the Lafayette catalog, and mentioned
in reviews (though I've always wondered if some of those reviews got
it wrong, and they weren't mechanical filters). But they were never
commmon. They were cheaper than Collins filters, but I have no idea how
absolutely cheap they were for the time. I don't recall coming across
real specs in the old magazines, either. I also recall in recent years
that it was those other filters that used foam rubber inside, and by
now much of that has deteriorated.

Michael VE2BVW


I had that happen with the filters in my NRD-515 JRC receiver.
Fortunately, it wasn't too difficult to open the filters up, which
allowed me to dissolve the old foam rubber
blanket that cushioned the mechanical filter elements. The
foam had to decayed to a chewing gum consistency and the
filter losses skyrocked. These were late 70s or early 80s
vintage IIRC. Regarding the patent issues, I don't recall
the particulars.

Pete k1zjh