Hi folks
We have a digital repeater in the 420-430 MHz subband that is being
installed shortly on our site. I am concerned about the possible
interference to systems in the 440-450Mhz subband on the same site.
What experience have you folks had with similar systems and
installations? What
I just realized that we also have another commercial analog repeater in
the 420-430MHz band, so close in sidebands would also be a concern.
Burt VE2BMQ
Burt Lang wrote:
Hi folks
We have a digital repeater in the 420-430 MHz subband that is being
installed shortly on our site. I am
What diameter are the rods? The older Sinclair VHF Hi cans used 5/16in
diameter whereas the newer cans used 1/4 in daiameter.
burkleoj wrote:
Glenn, I need 6 of them for a Sinclair duplexer that I have.
Someone cut the rods off when it was originally on a commercial
frequency. The rods in my
Hi Paul
Did I hear my name mentioned??? Maybe just ESP:-)
Some time ago the ISP I originally used merged with anther. I had files
on another ISP (rocler.qc.ca) but dropped it due to a dispute concerning
SPAM filtering. All my files that I kept have been moved to my own
domain website
The units I have seen appear to have a 1/2 wavelength of cable. The
loops are typically 1/8 wavelength equivalent and with 2 loops and the
cable will equal 3/4 wavelength. I have also seen some of the old
(rounded top) Sinclair cans with side connectors joined together with
only a double
The high resistance wire is nichrome.
As I recall its attenuation is around 20 dB/100ft at 2m. I built an
attenuator using it about 35 years ago. It handled the maximum power
rating of the coax as long as the first 10 ft from the input was well
spread out to prevent build up of heat.
There
The low-band loop from Sinclair (SRL 110) was not nearly as wide band as
the Hi band (SRL210) and UHF models (SRL310). The latter were designed
to be mounted either half wave or quarter wave from the tower or mast.
In the case of the low band loop a half wave would have put the loop 10
ft
The technique to match the natural 300 ohm impedance of a folded dipole
to 50 ohms simply uses matching section of an electrical 1/4 wavelength
of 125 ohm coax (RG-63B). It is usually installing inside the dipole in
order to be able to weatherproof the dipole easily at the feedpoint but
I
Actually 300 ohms is special. It is the impedance of a folded dipole
with equal diameter elements, the end result of bending a single piece
of tubing into a U. And the impedance is not affected by the spacing
between the elements (according to the handbook theory).
Burt VE2BMQ
John Sehring
the thinking stage.
Burt VE2BMQ
--- On *Thu, 8/27/09, Burt Lang /b...@gorum.ca/* wrote:
From: Burt Lang b...@gorum.ca
Subject: Re: [Repeater-Builder] 2 meter folded dipoles for multi bay
design information needed
To: Repeater-Builder@yahoogroups.com
Date: Thursday
Some thoughts from past experience.
Sinclair Q202 cans are not high pass OR low pass, they are both. They
have 2 notches, one on either side of the pass, separated by typically
10 MHz more or less. The 2 notches move as a pair by varying the series
capacitance on the loop. The more capacity
I would suggest anyone interested in this subject should Google Ufer
ground and get the real facts on the subject. The key to the concrete
encased ground electrode is a properly installed rebar reinforcing in
the concrete base.
Burt VE2BMQ
Ed Bathgate wrote:
I'm going to disagree
Hi Paul
The info I gave you applied to the SD214 series antennas (old SRL210A4
oe 210C4). I am guessing that it would also apply to the cheaper SD2352
series.
Let's hope you don't need to get inside the dipole itself. BTW what is
the diameter of the aluminum tubing used on the SD2352? The
Paul Kelley N1BUG wrote:
Hi Burt,
snip
You could try using 3/4 wavelength matching pieces to get the extra
length. That should be equivalent to 1/4 wave but will be more
sensitive to frequency changes.
I only need to extend them by about a foot to get ideal spacing
between dipoles,
Keep in mind that the 22S and possible the other variations had a
problem of intermittant solder joints on the steel pins that were used
as feedthrus on the circuit boards.
Burt Lang
Greg Beat wrote:
The Icom IC-22A is crystal-controlled, so has ultimate flexibility (at
the price
the mast and is beyond the means of us amateurs. However an external
harness is very practical.
Burt Lang VE2BMQ
Paul Kelley N1BUG wrote:
That's what I thought Chuck. Thanks! I haven't yet decided whether I
want to rip the heat shrink tubing off an element and disassemble it
to see what
Comprod's main plant is located in Boucherville QC on the Montreal south
shore. Like Sinclair, they appear to have a american branch plant to
supply the Made in America demand that was opened in 2005. It is
located near Buffalo in Orchard Park, NY.
Burt VE2BMQ
Gran Clark wrote:
Lee
Somewhere in my pile of data books I have an application note that
refers to a simplex repeater being used in commercial applications.
The booklet was from either dB Products or Pye as I recall. The purpose
of their simplex repeater was to fill local coverage holes. The
equipment described
The MASTR Exec (1) came in two flavors (at least here in Canada), the
Exec with a tube final and the Royal Exec with a solid state final. The
receivers in both cases was very similar. The receivers are very
sensitive and also quite tough. I saw one where the input trace on the
circuit board
I have found a simple way to verify if noise is coming from a power line
arc-over. Any such noise generated by a power line will only occur as
the voltage on the line approaches peak and it will be synchronized to
120 Hz. Put an oscilloscope on the audio while feeding an unmodulated
carrier
with the heat.
Burt Lang VE2BMQ
Fine except for one problem. Water is an excellant absorber of the
microwaves used in the microwave ovens (2.45 GHz) So your water will
heat up quickly irregardless of the coating. The only substances that
are better absorbers of that frequency are animal or vegetable fats
because they
in the foam for it to heat up and
probably melt leaving a real mess to cleanup.
Burt
MCH wrote:
You don't care if the cup of water heats up - you are looking to see if
the painted cup heats up. The water is only there to prevent burning out
the microwave.
Joe M.
Burt Lang wrote:
Fine
or nothing in it.
Burt
MCH wrote:
You don't care if the cup of water heats up - you are looking to see if
the painted cup heats up. The water is only there to prevent burning out
the microwave.
Joe M.
Burt Lang wrote:
Fine except for one problem. Water is an excellant absorber
I have found that adding a resistor in series with the fan and a
capacitor across the fan will do the same job as an inductor and
capacitor without taking up as much space. The value of resistor I use
is just enough to drop the voltage by about 1/2 volt. For a fan drawing
0.5A, use a 1 ohm
Delrin (polyacetal) is a bad choice for RF applications. Its
dissipation factor is too high. It is a great engineering plastic
meaning it is strong physically but it is too lossy. Teflon (tm) is the
best, also rexolite for RF. Also most any ceramics. Corning has a line
of machinable
wpp3 wrote:
Read the posts here already and wish to clarify a few things. First I
am in the process of converting a Q202G from the 160mhz range down
into the 2m band, specifically 144.7500/145.3500Mhz. I have found
that I will need to replace the harness to do this as it will not tune
down
There is an another option. PacComm had a 4 channel A-D converter board
for their Tiny-2 TNCs. It operated with the TheNet X1JR4 node software.
Each of the channels had adjustable scaling to yield whatever numbers
you wanted on the output. It has been a while since I have been
involved with
I would halve the power, tell the users that you have doubled the power
and watch the glowing reports of greatly improved performance roll in. :-)
That was the results I got 15 years ago when I tried the experiment.
Burt VE2BMQ
Tony L. wrote:
I've asked this question before, but will ask it
lpcoates wrote:
Hi
I'm helping a friend who wants to convert a Sinclair Res-Lok 4 cavity
combiner into a duplexer. Basically turning it into a Q2220E I
think). As far as I can tell, it should be possible by simply adding a
vatialbe cap to the coupling loops. I still haven't found
You might try Dataradio Inc. They took over the EF Johnson data radio
line as I recall.
www.dataradio.com/
Burt VE2BMQ
kb4mdz wrote:
Anyone have any info on alignment, etc. on a E.F. Johnson DL-3410
radio, Receiver or Transmitter? Got one of RX, two of TX, and am
trying to decide on
According to an old Sinclair datasheet, the 2B indicates a frequency
range of 132-150 MHz, the trailing D indicates 3 in cans and the O5 is
an engineering number. Looking at Q-203D specs shows 3 MHz min spacing,
0.6dB insertion loss and 65 dB isolation.
Hope that helps.
Burt Lang VE2BMQ
3M (or Scotch) 425 on 2 rolls of aluminum tape I have of different widths.
Burt VE2BMQ
Jeff DePolo wrote:
I bought my last rolls of filament tape and aluminum tape from Tessco. They
were OEM'ed by 3M but sold as Decibel products. If you can't find them,
I'll see if I can get a 3M part
it on or off.
I used to be the packet Guru but it has been a while since I looked at
the X1J documentation. If you are interested, I could look it up.
Burt Lang VE2BMQ
Past Tech chairman of the late NEDA (North East Digital Assoc).
knightdriver54 wrote:
I was wondering if anyone in the group
Keep in mind that there are two notches, one on each side of the pass.
They are spaced about 10-15 MHz apart. When the low notch is at 146MHz,
you will find the upper notch in the 154-156MHz area roughly. The reject
coaxial capacitor (or the piston cap in the newer version) adjusts both
The 10pf would probably work for the cans where the notch is on the low
side of the pass ie hi-pass BpBr. The capacity required for the notch
on the high side is 20-30 pf. I have paralleled 3 of the 10pf caps
(which can be had surplus for $1 or so each) to replace the 30pf caps.
It does help
Burt Lang wrote:
The 10pf would probably work for the cans where the notch is on the low
side of the pass ie hi-pass BpBr. The capacity required for the notch
on the high side is 20-30 pf. I have paralleled 3 of the 10pf caps
(which can be had surplus for $1 or so each) to replace
. It does not sound like what you were asking for. Are you sure
about the number?
I have an index of Ap Notes and bulletins dated 1989 and I don't see any
reference to an R100 PLL. Can you give me a Motorola MCxx device
number?
Burt Lang
Barry Buelow wrote:
The data sheet I have lists only
Do you by chance have an AN- number? in the 1980s I used to
subscribe to all the Motorola documents and still have most of them in a
box.
Burt VE2BMQ
Barry Buelow wrote:
Hello
Does anyone have a copy of the Motorola App NOtes for PLL from about
15+ years ago? I'm looking for some
Hi folks
I have heard that the military will not allow BNCs on RF connections
because the bayonet connection on the outside shell allows the ground
side of the cable to vary (wiggle) and be noisy. BNCs appear to be used
for data and low freq but TNCs are specified for RF use.
Some years ago
Another possibility are 12v RV incandescent lamps. A 50w lamp will draw
4 amps. Hook a bunch of sockets in parallel and screw in the number of
lamps necessary for the desired load. The light will remind you that
the load is still connected and you don't need a cooling fan.
Another
If you ever do install the amp, I would suggest lying to the users when
it goes on line. Tell them that it is on low power when it is on high
and vice versa but don't announce it the instant you change. Wait a
while before announcing it. You will very quickly find out who can
actually tell
Hi guys
I have bought a number of the Lambda modules at fleamarkets usually for
a dollar each or so. There are two sizes, a low power one designed to
fit onto the 5-7 amp supplies and a high power one designed for the 24+
Amp supplies. The differences are mainly in the size of the SCR.
I
a overall length of 22in and they have a 3 MHz min
spacing and 65 dB attenuation.
Burt Lang VE2BMQ
Laryn Lohman wrote:
--- In Repeater-Builder@yahoogroups.com
mailto:Repeater-Builder%40yahoogroups.com, Burt Lang [EMAIL PROTECTED]
wrote:
What length are the cans? According
What length are the cans? According to Sinclair's old Duplexor
nomenclature from a 1973 datasheet, that the 2B indicates a 132-150 MHz
range. The O5 are Engineering numbers and the D = 3in cavity size.
Does any of that make sense?
Burt VE2BMQ
Laryn Lohman wrote:
I am looking for specs
One technique that I have used occasionally has not been mentioned yet.
Assuming the the core has a hex hole in it, you choose an metal hex key
(allan wrench) of the right size to fit the core and heat it very hot
with a torch. Then place the key in the core and let the heat transfer
to the
or a 22 caliber cartridge!!! According to the Darwin Awards, someone
actually tried that. It didn't kill him but his ability to transfer
genes in the future was severely limited :-)
Burt VE2BMQ
Chuck Kelsey wrote:
How about an aluminum foil gum wrapper wrapped over a fuse. I've seen
Any spread spectrum systems nearby??
Burt VE2BMQ
Gary wrote:
I have an interesting thing happening on our two meter repeater. We
have what appears to be a blanking white noise that is present on the
input. The repeater is a split site system with a 440 link from the
two meter receiver
What you are experiencing is the symptioms of insufficient capacity to
pull the notch down low enough on the low pass side. The capacity range
of those tuning stubs is determined by the length of the center rod
inside the plastic stub. They are 3/16 (I think) diameter brass rod with
a
You say a drawer?? I have a manual on a Harris CT-1555 VHF/FM car
telephone. According to the spec sheet the FCC approvals on the RX and
TX modules are the same 1555A1. If it is in a drawer, maybe it is some
kind of a remote base or something operating in the same MTS or RCC
phone system
Is it the interconnect cable that is heating or is it the can that is
heating and transferring heat to the cable?
I had one case of a Sinclair duplexor where one can was heating at least
20 deg warmer than the remaining 3 cans. It turned out to be a lossy
ground connection where the center
Sinclair 210C4 speced at 138-1741.5:1 They are the standard antenna
used in multicoupled systems here in Canada. I have seen one with as
many as 28 frequencies coupled into it.
Burt VE2BMQ
[EMAIL PROTECTED] wrote:
Have a question for the list. Is there an antenna (VHF) that will cover a
The SRL235 series with its double dipoles side by side on each side of
the mast doesn't have any connection with the SRL210 series unless it is
in the way that the feedline is terminated at the element (the picture I
see in their catalogue looks like an internal termination like the 210
It is a Johanson model 5602 1-30pF. They are not easy to find and
expect to pay 10-15$ for one.
At times when I needed a replacement, I modified the disk to take 3
Johanson 5202 1-10pF trimmers in parallel which are much easier to find
cheap. They may even be higher Q than the single unit
They are definitely Sinclair, welded top, side loop BpBr cans. They are
an intermediate design between the old rounded top, spun aluminum cans
with side loop and the welded top, top adjustable loop design of the
modern Sinclair cans. They date from the late 50s or early 60s (by 1964
or so
Try using 0W-30 fully synthetic oil in the crankcase. I find that that
does not thicken nearly as much as regular 5W-30 oil in my generator. I
can normally spin it easily even at -20.
0W-30 synthetic is not easy to find but I did find some at Wal-Mart in
the past and Esso has some called
?
Chuck
Burt Lang wrote:
Try using 0W-30 fully synthetic oil in the crankcase. I find that that
does not thicken nearly as much as regular 5W-30 oil in my generator. I
can normally spin it easily even at -20.
0W-30 synthetic is not easy to find but I did find some at Wal-Mart in
the past
A few years ago a couple of large gensets were stolen from a
construction site here in Quebec. 6 months later the police raided a
farm a couple of miles from me and took down a marijuana grow-op. Seems
the gensets had been equipped with what is locally known as a
Boomerang system, a
The Johanson 30 pf trimmer is very rare in surplus but the 10 pf
trimmers are very common and cheap (as little as 50c-$1 each) in
surplus. I have bought a few hundred over the years, mostly at
fleamarkets. I have used 3 10pf trimmers in parallel to replace the 30
pf trimmers in Sinclair cans.
Hi guys
With all this talk about 6m antennas, can I mention that I have a pair
of Sinclair SRL-110 dipoles to dispose of. They were used in a
commercial system at 48/49 MHz. I have not tested them at 52/53 MHz but
the SRL-x10 series antennas are usually quite broadband.
The catch is that
Is the scope in the CE5 a plug-in model 301 module? If so, the CRT is a
3RP1A tube. If not that module, please disregard.
Burt VE2BMQ
hwingate wrote:
The CRT display in my old CE5 has gotten so dim that I have to turn
the lights off to use it. Does anyone know the CRT tube number used
As a general rule, the outer can has to be at least a can radius longer
than the center resonator ie a 6 in can must be at least 3 inches
longer than the resonator. There is no maximum length requirement on
the outer can.
Burt VE2BMQ
Jeff DePolo wrote:
Probably not. You would run into
I don't know what a 74-70 is - my old TXRX catalogue does not list it.
But I have converted a TXRX 4 can multicoupler to a 2m BpBr Duplexor for
a local club quite successfully. I will discuss it with you off-list if
you are interested.
Burt VE2BMQ
wa9ba wrote:
I was wondering if anyone
Per Molund wrote:
I am trying to retune an Sinclair Q2330E duplex filter to 145 MHz
(145.1375/145.7375) from it's factory configuration of 150 MHz
(150.83/149.80), however the notch atenuation is strongly reduced.
There is also impossible to set ut the proper bandpass/notch
How much do you need? Does anyone know what it is worth on the market
as I have 600-700 ft that may be surplus to my needs. I will have to
hunt it up and check the type number.
Burt VE2BMQ
DCFluX wrote:
Anyone know where I can get 1/4 hardline? Either Super Flex or Regular?
I assume that this duplexor is the model with rotatable loops on the
flat welded end of the cans (as opposed to an earlier model with side
loops and rounded can ends). From my experience, if the loops are too
tightly couplied, it is difficult to get the notch close to the pass.
Try reducing
Hi Adi
At VE2RM (Rigaud, QC) we have been doing that since 1986 with a 145.01
digi on the same antenna as our 146.400TX/147.000RX repeater. Spacing
is similar to what you want to do. We are using a clone of a Sinclair
C-series multicoupler (3 6in pass cans and one notch can) that is
I think the original question was about a Jones or Cinch-Jones plug. I
have a large number of various sizes. Which one was being looked for?
Burt VE2BMQ
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I have used Advanced Alloys in Deer Park, NY in the past to get Invar.
http://www.advancedalloys.com/
Look under Corrosion Resistant and High Temp Alloys - Rod for Invar36
(Invar is 36.15% nickel, remainder iron)
Normally rod is stocked in 12 ft lengths but they cut my orders to 6ft
so that it
The name INVAR was coined by the man who discovered it, a Mr Guillaume,
and is not a tradename. The main manufacturer of INVAR is Carpenter
Steel Co.
I just checked with the Metals Handbook, 8th Ed, published by the
American Society of Metals, Volume 1, chapter on low expansion alloys
and
You don't even need an S-meter. The background noise level will vary
inversely with the signal level and as you approach zero beat, the noise
will flutter slower until it rises and falls very slowly. It is just as
accurate as using an S-meter. I have used that technique many times on
my freq
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