It's kinda tough to measure when you don't have all the pieces in front of
you. I'm space constrained so I'm looking for alternatives to conventional
designs.. 3 harmonic filters take up a lot less space than 3 cavity filters.
I'm attempting to stay conventional up to a point.. we can look at it
On Oct 23, 2007, at 12:42 PM, Jeff DePolo wrote:
Jeff,
A diode is most certainly an active device. Its properities
change with exciting voltage and follow many parameters just
as a transistor.
A diode is NOT an active device. It's properties changing with
applied
voltage do not
Hey guys. I have a question on schematics or a wiring diagram.
I need to wire up an NHRC-5 Controller to an old RCMP VHF Motorola
MSR-2000 (40 Watt version).
I was going to wing it, thinking I could go through the squelch gate
but, I would rather look for some information. Has anyone done this
I'm basing those isolation figures on a calculator I found online that asked
for the gain of the antennas and the separation (horizontal or vertical)
Re splitting the simplex: a circulator with the radio hooked to the input,
the transmit chain on the standard output, and the receive chain
I've seen dual stage isolators (have one sitting here for 440 just in case I
get a UHF pair to work with), and am actually planning to use them as
exactly that on each transmitter... and I've proposed your idea if worded
slightly differently by suggesting a circulator between the combined output
On Oct 24, 2007, at 12:37 AM, John Barrett wrote:
Re splitting the simplex: a circulator with the radio hooked to the
input, the transmit chain on the standard output, and the receive
chain feeding the load port is what I was thinking – a relay would
do the job just as well, but would
Nate,
As defined in many publications, one being Electronic Engineers Handbook,
Donald G Fink Any element which receives energy from some source other then a
signal generator is an active element. Any element to which energy is supplied
by other part of the circuit is a passive element, also,
Jeff,
Beta is the current gain of a transistor, HFE and Hfe. No one would design a
transistor with a beta of less than one, but they do exist for transistors can
become defective. It is common for a new transistor to have a beta of 100, but
after hours of use decrease to 20. A good design
It wires like any other controller..
The RB site has some really good notes.
atms169 wrote:
Hey guys. I have a question on schematics or a wiring diagram.
I need to wire up an NHRC-5 Controller to an old RCMP VHF Motorola
MSR-2000 (40 Watt version).
I was going to wing it, thinking I
OK - Here are my requirements for the transmit chain. minimal
physical space and minimal insertion loss :-) (ok - too
bloody obvious) Tuning simplicity is also a factor. I'm
combining 3 transmitters at 144.39, 145.05 +/- 0.04 and 145.25
snip
Can you list out some of the other options that
Jim,
I agree with you. Going to UHF for the repeater greatly simplifies things and
UHF pairs are often much easier to find.
Also, one reason 145.25 might be open is it is the cable channel video carrier
freq. Tune in many areas and you get a constant usually pretty strong signal.
Tone is
On Oct 24, 2007, at 5:56 AM, Ron Wright wrote:
An active element does not have to have gain. I have designed op-
amp circuits which had no voltage, current or power gain and these
are most certainly active elements. The last I designed was to
covert the roll of a B52 aircraft from it
John,
If I'm reading this correctly, you're trying to do this all in a trailer -
yes? Since you are operating portable, does your coordinating body have
an Itinerant UHF pair you can use for the repeater? If so, this might
make your situation MUCH easier to engineer.
Mark - N9WYS
OK - let me throw a little more gas on this fire... Just for giggles, I
went to Mouser Electronics, and selected their page for Passive
Components.
http://www.mouser.com/search/Refine.aspx?Ne=254016+1447464N=1323038%2025427
1Ns=P_SFieldRefType=Header
Guess what?? Capacitors are listed
Well I finally got the courage to tear apart my duplexer. The spring
and finger stock appear to be in excellent condition with good
contact pressure. However...
If you look at this picture:
http://www.n1bug.com/cavity.jpg
You can see the end of the tuning plunger. The tuning rod is
soldered
Paul,
I have seen similar construction in cans. All of the ones I have seen have a
small plastic grommet insert in the hole in the top of the plunger. It's a
plastic insert like would be in a hole where wire passes through it. They
are available at Lowe's and other hardware stores.
I also
OK, I have to comment,
An isolator/circulator should not be used in a duplexer at the antenna
connector when there are other strong signals floating around the air
that can get into the isolator. The strong transmit signal will mix
with off air signals in the circulator BECAUSE IT IS NOT LINEAR
At 09:51 AM 10/24/2007, you wrote:
OK, I have to comment,
An isolator/circulator should not be used in a duplexer at the
antenna connector when there are other strong signals floating
around the air that can get into the isolator.
---Uh...a couple of things here:
1) Did I miss something
Thanks Scott,
I really appreciate the reply!
I find it extremely strange the knobs are soldered on also. You're
probably right, although these knobs sure look identical to the ones
in all the old Decibel Products catalogs, etc. But these knobs have
NO holes for set screws or anything of the
At 10:10 AM 10/23/2007, you wrote:
No, it's not linear. First off, it doesn't satisfy the superposition
principle since it will produce harmonic when fed by a pure sinusoid carrier
(hopefully we can agree to that without added discussion), so right off the
bat it's nonlinear. Furthermore, it's
So according to your definition of active that would mean that a regular
old ammeter is an active device as something changes when a signal is
applied.
That would also make a light bulb an active device as its properties change
when a signal is applied. Its resistance changes, it gives off heat
Yes - this is going on an 16ft boat trailer converted to a flatbed with a
38ft crank up tower mounted on a tilt base that I built. the tilt base,
hydraulic system, and generator are towards the back of the trailer, with a
9ft x 5ft x 3.5ft cargo box system forward of the tilt base. The forward 5ft
At 10:10 AM 10/23/2007, you wrote:
I thought it was linear unless it becomes saturated. Circulators are
ferrite devices and as long as the ferrite core isn't saturated, it
remains linear.
One other thing. If the use of ferrite alone was the sole
requirement to determine linearity, then I
Replace the duplexers antenna tee with a circulator. Tune the
circulator as follows: Port A to B to pass TX frequency, port B to C
to pass RX frequency. Port A to Port C isolation should be in the 20dB
range or better and it still protects the transmitter and helps with
mixing. RF from the antenna
Yes - I made that suggestion. I'm no RF engineer, but it seemed like an
interesting idea. A circulator configured as an isolator (dummy load on the
3rd port) would be counterproductive, my idea was to hook the 3rd port to
the receive chain, adding the reverse port to port isolation of the
Ohh geez - active devices are capable of exhibiting gain. Period. I hate to
sound proprietary, but I started this thread and this is WAY OT !!
_
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Gary Schafer
Sent: Wednesday, October 24, 2007 11:42 AM
To:
Ron Wright wrote:
Also if packet on VHF and repeater on UHF a simple crossband coupler
and dual-band antenna will simplify things.
73, ron, n9ee/r
Yes-greatly!
--
Jim Barbour
WD8CHL
Gary,
Might be correct about a light bulb. Some would say it is active, hi. However,
its material is not changed, just heated up. The amp meter does not change its
parameters, just reacts to a signal similar to an inductor.
A diode's atoms change and react to applied signal unlike a
Gary,
Might be correct about a light bulb. Some would say it is active, hi. However,
its material is not changed, just heated up. The amp meter does not change its
parameters, just reacts to a signal similar to an inductor.
A diode's atoms change and react to applied signal unlike a
Mark,
Also listed were oscillators, hi. Not sure if I would rely on a catalog
especially Mouser for a definition. Sometimes one will find more than one item
on a page, hi.
I do like Mouser. Good to see a company where small quantity can be found. I
like Digi-Key little bit better.
Nate,
Ok,
73, ron, n9ee/r
From: Nate Duehr [EMAIL PROTECTED]
Date: 2007/10/24 Wed AM 10:25:31 CDT
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: duplexer isolation and reciever noise
On Oct 24, 2007, at 5:56 AM, Ron Wright wrote:
An active
There are several articles on converting an MSR-2000 to amateur repeater
service on the Repeater-Builder website, under the Motorola Mitrek/MSR-2000
pages, that include pinouts for connecting an external controller. Take a look
at:
Also---Just FYI* I will be submitting articles to RB on hooking up a
TS-64 toneboard to an MSR-2000. Say hasta la swago to reeds...
I also plan on doing a real down and dirty guide on interfacing to the
analog MSF-5000...
George Henry wrote:
There are several articles on converting an
Progress!
Scott, or anyone...
I got one of the knobs off. Removing them is not such a big deal as
I thought. It turns out the brass insert in the knobs is threaded.
They are screwed onto the rods AND soldered. Sheesh!
The hole in the top metal end plate of the plunger is indeed just a
little
Paul,
Excellent photos!
The only reason these two pieces of metal have began touching each other is
that the invar plunger or the silver tuning sleeve have become bent.
This could be due to some rough handling of the unitsprobably when you were
absent?
Personally, I would drill a series
Let's not forget about Skipp's article. I used it one time and it works quite
nicely...
http://www.radiowrench.com/sonic/so02004.html
Shane KI4M
George Henry [EMAIL PROTECTED] wrote: There are
several articles on converting an MSR-2000 to amateur repeater service
Hi All,
I am trying to get the Zetron 38 running on our local 2 meter
repeater (only as a temp measure) due to logic problems
What I want
Morse ident out every 15mins as to comply with the regs, the ident
does go out but no radio tx any thoughts
Station ID
At the moment the station id
Paul N1BUG wrote:
I still can see no other possible source of the noise/desense in
this cavity.
Just a sanity checking question...
You were able to get the cavity to misbehave OFF the site and hooked to
completely different interconnect cables and a different radio, right???
You've also
Thanks Ian.
I've realized my idea of soldering these two pieces together is
horrible. The length of invar rod from the top of the cavity to its
bottom attachment point may be critical for temperature compensation
of the cavity! I can't believe I was proposing to do such a thing!
Looks like I
Nate,
I appreciate the sanity check. I've been known to overlook things
like that and make some fine blunders!
The gouges you refer to appear to be tool marks of some sort. What
you can't tell from the photo is it looks like they were made BEFORE
it was silver plated, so I'm assuming some
Working ICOM RP-4020 UHF 50 Watt repeater with blown power mod.
$1000.00 plus shipping
3 comspec TP-3200 repeater tone panels in 1u tri-shelf
$500.00 plus shipping
RLC-3 (1.80 or 2.15 I forgot which) with 3 radio cards (old style) in
it and an autopatch card.
$1000.00 plus shipping
[EMAIL
what you are talking about the ID in DTMF and the time factor are all in
programming. I don't have a book on the unit here but it all can be done.
John
- Original Message -
From: radiotech808
To: Repeater-Builder@yahoogroups.com
Sent: Wednesday, October 24, 2007 4:18 PM
Just as a suggestion, I would try stabilizing the rod temporarily and, with the
assembly put back
together tap on it to see if the problem is still with you.
73 de Jack
- Original Message -
From: Paul N1BUG
To: Repeater-Builder@yahoogroups.com
Sent: Wednesday, October 24,
John,
Thanks for the reply
One thing I do have is the manual although not all DTMF programming commands
work with my panel still suspect it's a hardware issue
Will speak to Zetron tomorrow see what they come up with !
Regards
Al
Maire-Radios [EMAIL PROTECTED] wrote:
do you have one of the follow and the book for the other as there are: 38 38A
38max and there may be 2 ver of the plan 38.
John
- Original Message -
From: ALASTAIR GRAHAM
To: Repeater-Builder@yahoogroups.com
Sent: Wednesday, October 24, 2007 7:18 PM
Subject: Re:
Hey Paul, another ham in my area had our DB4062 apart earlier this year for
a similar problem lots of rx noise when I wiggled on two of the tuning knobs
in the rx chain. He reported it to be discolored inside on the threads and
rod but no pits and he cleaned them up. I will try to reach him and
145.25 can be a real pain. We have a repeater on that frequency. It is CATV
channel E. We always have leaks from the cable rendering the repeater
useless in some areas until a call is made to the CATV plant. They go out
and tighten the screws on an amplifier (left loose by the last tech working
Again, the circulator will produce intermod when external strong
signals enter the antenna port when used as a switch for the duplexer
and there is transmitter power also going through it. 50 Watts or
47dBm to -116dBm receiver sensitivity is 163dBm dynamic range. The
device is not linear
We had a 1500 watt 70 MHz circulator go bad. I disassembled it to see what
failed. IIRC there were 9 capacitors and at least 3 inductors along with
the ferrite ant tuning magnets. Really makes a TV transmitter quit when the
circulator between driver and final fails. Quite a site to see the
You have to read carefully -- I said capable of gain. Not
designed into the circuit in such a way that they EXHIBIT gain.
Thank you.
I can tune an otherwise-functional transmitter such that it takes in several
kW of DC power and gives me practically zero RF output. That doesn't make
the tube
Beta is the current gain of a transistor, HFE and Hfe.
Finally something we can agree on. But the way you used beta was
referring to the net gain of a *circuit* using a transistor in
emitter-follower
configuration, which I don't think is the correct use for the term, and
which is why I put
I would consider anything that uses a semi-condutor material to be
active, Silicon and Germanium transistors included.
On 10/24/07, Jeff DePolo [EMAIL PROTECTED] wrote:
Beta is the current gain of a transistor, HFE and Hfe.
Finally something we can agree on. But the way you used beta was
At 10/24/2007 10:08, you wrote:
At 10:10 AM 10/23/2007, you wrote:
No, it's not linear. First off, it doesn't satisfy the superposition
principle since it will produce harmonic when fed by a pure sinusoid carrier
(hopefully we can agree to that without added discussion), so right off the
bat
At 10/24/2007 10:55, you wrote:
Gary,
Might be correct about a light bulb. Some would say it is active, hi.
However, its material is not changed, just heated up. The amp meter does
not change its parameters, just reacts to a signal similar to an inductor.
A diode's atoms change and react to
I think the ID in DTMF you are talking about is the user ID which is
transmitted at the end of a transmission as the bubble up. The DTMF sequence
is the user number.
If you want to have the Z38A transmit an ID every 15 minutes in Morse whether
it has been active or not, put a user number
At 10/24/2007 19:46, you wrote:
145.25 can be a real pain. We have a repeater on that frequency. It is CATV
channel E. We always have leaks from the cable rendering the repeater
useless in some areas until a call is made to the CATV plant. They go out
and tighten the screws on an amplifier (left
Hi all,
I have been given the following items, and all appear to be in working
order.
KEY KF150 Base @ Repeater unit (Kyodo KG110-15A) apparently
Matching PSU for above
Zetron Model 38-Max repeater panel
Sigma SDX 150 duplexer
As per the subject line I am a complete newbie to this kind of
Anyone with any experience turning a VHF PURC 5000 into a repeater?
Randy
I was looking to go this route for a long time. If you can plug a local
mic into the PURC, then you could use a maxtrac as RX and just put a
controller in between.
wb0vhb wrote:
Anyone with any experience turning a VHF PURC 5000 into a repeater?
Randy
--
Jay Urish W5GM
ARRL Life
Wikipedia is only as good as the person writing the entry.
Who here thinks a varactor tripler is not active? Sure, it's not that
efficent, but 10W of UHF to make 3W of 1.2GHz is a pretty impressive
feat.
On 10/24/07, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote:
At 10/24/2007 19:26, you wrote:
I
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