Late Mitrek boards still SPECIFIED different reeds, but I agree
that they seemed interchangeable. In every case I saw no difference
between TLN6824s, KLN6209s and KLN6210s. Just as a test I removed
the reed hold down post on a Mitrek board and plugged in a TLN8381 fat
decode reed into the decode socket and saw no change in performance.
I've found that except for the old big copper cased reeds that
most small reeds are very interchangeable.
Yes, some combinations have sensitivity issues and a few result in
situations where it just doesn't work.
You aren't going to break anything or burn anything up by plugging
in the "wrong" reed.
And if you are paralleling decode reeds (to get an OR situation on
tone decode) sometimes you need to change a resistor value or two.
One weird thing is, with some reed / board combinations I've found
that you can get big jumps in decode sensitivity just by rotating
the decode reed 180 degrees in the socket, and sometimes you
can get a reduction in distortion of the encode tone by rotating the
encode reed in the socket.
Since I discovered this phenomena I always rotate the decode reed
in it's socket and leave it in whichever position that has best decode
sensitivity.
While the receiver is on the bench (in carrier squelch mode) just
reduce the signal to maybe 8 to 10 db quieting SINAD, then enable
the tone decoder and raise the PL tone level until it just decodes and
note the level. Then rotate the reed and do the same check again,
and leave the reed in the better spot. This doesn't happen in every
case so don't be disappointed if the two numbers are the same.
Measuring encode tone distortion is a bit more difficult for the average
ham, but I used to key the transmitter, lower the tone encode level until
it just dropped out, rotate the reed and key it again. The position that
allowed the lower level is where I left it. Then I reset the level. And
before I got good test equipment I'd do that check on the air and just
listen full duplex.
I don't know why some reeds (ore reed / board combinations) do
that, they just do.
No, I'm not advocating using this trick to reduce encode levels.
If you have a decent high pass filter (i.e. PL cut filter) in the receiver
then you aren't going to hear 600 Hz (or even 900 Hz) of PL deviation.
I am advocating getting the best performance on PL decode sensitivity
and encode distortion, especially when the only cost is a minute of
your bench time, or less, to rotate a reed and twist a level control.
Mike WA6ILQ
At 04:24 AM 08/10/10, you wrote:
Sorry, maybe. It's heavily application dependent. While senders
*tend* to be higher level lower loss devices, that difference
diminished over time. On some newer devices it seemed like the only
difference was the label. The very alst applicaitons before
Motorola caved adn went all electronic used one device type in all
applications. Late Mitrek PL boards are an example.
On 8/10/2010 6:20 AM, Captainlance wrote:
Sorry, NO. A sender will not work as a sponder.
----- Original Message -----
From: <mailto:wb6...@verizon.net>Eric Lemmon
To:
<mailto:Repeater-Builder@yahoogroups.com>Repeater-Builder@yahoogroups.com
Sent: Monday, August 09, 2010 9:13 PM
Subject: RE: [Repeater-Builder] Can a KLN 6210A vibrasender be
substituted for a KLN 6209A vibrasponder?
Brian,
Yes, probably. The coils have different impedances, and the armatures have
different masses, but they are close enough that in most cases they are
interchangeable. That said, Motorola did make them different for a reason-
most likely that one was more sensitive as a vibrasponder, and the other
worked better as a vibrasender. I recommend that you use the specified part
for optimum performance.
73, Eric Lemmon WB6FLY
-----Original Message-----
From:
<mailto:Repeater-Builder%40yahoogroups.com>Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Brian J. Henry
Sent: Monday, August 09, 2010 11:34 AM
To:
<mailto:Repeater-Builder%40yahoogroups.com>Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Can a KLN 6210A vibrasender be substituted for a
KLN 6209A vibrasponder?
I have an MSR 2000 repeater that I want to change the PL frequency on. Does
anyone know if a KLN 6210A vibrasender will work in place of a KLN 6209A
vibrasponder on the MSR 2000 PL board?
Curiously,
Brian Henry, WB6QED
--
<mailto:o...@ozindfw.net>mailto:o...@ozindfw.net
Oz
POB 93167
Southlake, TX 76092 (Near DFW Airport)
