At 2/28/2007 08:19 AM, you wrote:
Bob
You seem to want to lump what is characteristically a complex impedance
(R+or-jX) into a single number in order to simplify your argument that a
non conducting RF output transistor is an open circuit because the
transistor is not having any RF drive
At 2/28/2007 08:19 AM, you wrote:
Bob
You seem to want to lump what is characteristically a complex impedance
(R+or-jX) into a single number in order to simplify your argument that a
non conducting RF output transistor is an open circuit because the
transistor is not having any RF drive
Since when is the Xc of the Collector-Base capacitance of an output transistor
or the Drain-Gate capacitance of a FET considered an open circuit at RF?
Allan Crites WA9ZZU
Jeff DePolo [EMAIL PROTECTED] wrote:
Bypassing the relay shouldn't have an effect on the TX output
Z when
At 2/27/2007 13:30, you wrote:
Since when is the Xc of the Collector-Base capacitance of an output
transistor or the Drain-Gate capacitance of a FET considered an open
circuit at RF?
Allan Crites WA9ZZU
OK, maybe not a million ohms but high enough compared to the nominal 1 ohm
or so output Z
Bob Dengler wrote:
At 2/23/2007 12:50 PM, you wrote:
With respect to using the GE MII mobile frame for repeater applications:
1. Can you say categorically that there is sufficient TX/RX shielding
to prevent any desense at any power level the conversion is capable of
operating?
In my
At 2/26/2007 08:27 AM, you wrote:
Bob Dengler wrote:
At 2/23/2007 12:50 PM, you wrote:
With respect to using the GE MII mobile frame for repeater applications:
1. Can you say categorically that there is sufficient TX/RX shielding
to prevent any desense at any power level the conversion
Bypassing the relay shouldn't have an effect on the TX output
Z when not
TXing, as the final RF output transistor is going to look
like an open too.
Bob NO6B
But the open transistors would be at a different electrical distance away
from the duplexer than the open T/R relay was.
Sent: Saturday, February 24, 2007 2:53 AM
Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?
(Z-Matcher)
At 10:19 PM 02/23/07, you wrote:
In a message dated 2/23/2007 6:36:24 P.M. Pacific Standard Time, [EMAIL
PROTECTED] writes:
In regards to the question
Yes, and as the article referenced below points out, switching the UHF
Mastr II to High Side Injection eliminates the problem.
We originally thought that HSI eliminated the problem totally on 220,
but it didn't, there is an overlapping range that one side or the other
doesn't fix; that is what
[EMAIL PROTECTED] wrote:
In a message dated 2/23/2007 6:36:24 P.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:
In my most critical applications, I use permanent in-line Bird
samplers. Then, cabling lengths don't change because I don't
remove the samplers; and you know exactly
I never suggested that the cable between the TX and the
duplexer had to be an exact length and if the TX output is a
true 50 ohms then any cable length produces no consequence at
the cavity input. But if the TX impedance is not 50 ohms, I
think any cable length other than half wave will
Ken Harrison wrote:
Thanks for the recommendation, Don. Though I'm sure a MastrII would
be a great conversion for 220, we (in the group sense) want to try to
save some of our money to get a remote base setup going on our
repeater, too. Our small savings would be wiped out to replace the
For Scott:
With respect to using the GE MII mobile frame for repeater applications:
1. Can you say categorically that there is sufficient TX/RX shielding to
prevent any desense at any power level the conversion is capable of operating?
2. When these converted mobiles operate with
[EMAIL PROTECTED] wrote:
For Scott:
With respect to using the GE MII mobile frame for repeater applications:
1. Can you say categorically that there is sufficient TX/RX shielding to
prevent any desense at any power level the conversion is capable of
operating?
At
] Re: 220 repeater receiver recommendations?
For Scott:
With respect to using the GE MII mobile frame for repeater applications:
1. Can you say categorically that there is sufficient TX/RX shielding to
prevent any desense at any power level the conversion is capable of operating?
2
In a message dated 2/23/2007 12:00:13 P.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:
It probably isn't exactly 50 ohms, but should be close. And the cables
from the duplexer to the radio do NOT *REPEAT* NOT need to be an exact
length. This again indicates an impedance mismatch in
Message -
From: [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Friday, February 23, 2007 4:06 PM
Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?
In a message dated 2/23/2007 12:00:13 P.M. Pacific Standard Time, [EMAIL
PROTECTED] writes
At 2/23/2007 12:50 PM, you wrote:
With respect to using the GE MII mobile frame for repeater applications:
1. Can you say categorically that there is sufficient TX/RX shielding
to prevent any desense at any power level the conversion is capable of
operating?
In my experience, yes. In
@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Friday, February 23, 2007 4:06 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?
In a message dated 2/23/2007 12:00:13 P.M. Pacific Standard Time,
[EMAIL
I'm not Scott, but maybe I'll do... grin
See Below
[EMAIL PROTECTED] wrote:
For Scott:
With respect to using the GE MII mobile frame for repeater applications:
1. Can you say categorically that there is sufficient TX/RX shielding
to prevent any desense at any power level the
In a message dated 2/23/2007 4:32:54 P.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:
as all better repeaters builders know, the equipment might have to be tuned
as a system using custom cabling lengths or Z Matchers for optimal
performance.
Can you comment on a difference of
[EMAIL PROTECTED] wrote:
I'm particularly interested in any shortcomings of the G.E. that are not easily
overcome.
Repeatability of a band split conversion, out of band (high-band to 222)
conversion, (where sensitivity is concerned) and tuning stability.
It seems that *some* MASTR II
_
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Kevin Custer
Sent: Friday, February 23, 2007 8:34 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: 220 repeater receiver recommendations?
[EMAIL PROTECTED] wrote
Weren't there some 440 frequencies that had issues, too?
Joe M.
Kevin Custer wrote:
I'm not Scott, but maybe I'll do... grin
See Below
Yes, there is sufficient isolation for single box conversion with
absolutely no internal desense from the MASTR II Mobile, with the
exception of
]
To: Repeater-Builder@yahoogroups.com
Sent: Friday, February 23, 2007 2:24 PM
Subject: Re: [Repeater-Builder] Re: 220 repeater receiver
recommendations?
For Scott:
With respect to using the GE MII mobile frame for repeater
applications:
1. Can you say categorically
In a message dated 2/23/2007 6:15:19 P.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:
Do you use a cable with the bird that makes it a ½ wavelength total line
length when you insert it in line? That should not change things when the
wattmeter/cable are removed.
I'm not sure I
In a message dated 2/23/2007 6:36:24 P.M. Pacific Standard Time,
[EMAIL PROTECTED] writes:
In my most critical applications, I use permanent in-line Bird samplers.
Then, cabling lengths don't change because I don't remove the samplers; and
you
know exactly what you have and where
At 2/22/2007 19:01, you wrote:
Ken,
We not only do complete repeaters, we can custom build just about anything
you want or need. We can simply build a rock-solid high-quality 220
receiver for you. We have done several receivers in the past that are rack
mountable in a 2 unit rack space. I have
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