RE: [Repeater-Builder] Re: Switching Power Supply vs. Astron Etc.

[N9WYS]

Thanks for the fine explanation, Eric!  

My main concern/wonder was in regard to the issue mentioned by Skipp, and a
perceived concern over damage that might occur as a result of the voltage
fluctuations.  I've even noticed dimming and brightening of the lights in my
house when this apparently occurs - I guess the issue is not as serious as I
thought.  Just trying to be cautions - maybe overly so.  ;-)

Thanks again!
Mark - N9WYS

-Original Message-
From: Repeater-Builder@yahoogroups.com On Behalf Of Eric Lemmon

Mark,

Sudden and regular changes in voltage levels on long lines are normally
caused by the switching in and out of capacitor banks that are used to
improve voltage regulation on long distribution lines.  This is most
commonly used on lines carrying 4,160 to 22,000 volts.  In areas where light
industrial loads are common, the power factor is lagging during most of the
day, due to the number of motors and other inductive loads connected.  To
counteract this lagging power factor, capacitor banks are switched in and
out by either a timer or a voltage sensor.  In my area, the nominal voltage
jumped from about 119 volts to 123 volts in the morning, and dropped back in
the late afternoon.

This practice is very important in rural areas, where a 12kV line might run
20 miles to a farm.  If regulators or capacitor banks were not used to
stabilize the voltage, there would be large excursions each time the farmer
started his irrigation pumps.  Motors, being inductive, cause a lagging
power factor that results in an increased voltage drop on the distribution
circuit.  The capacitors supply capacitive reactance that cancels the
inductive reactance and, when properly applied, will improve the power
factor to near unity and minimize the voltage drop.

Most well-designed power supplies, both linear and switch-mode, will
maintain a relatively stable output voltage despite wide variations in AC
input voltage.  Some designs are nearly immune to step-voltage changes
resulting from capacitor switching.  I don't think it's necessary to employ
a Variac or similar variable transformer to adjust the voltage.  If the
measured AC voltage at the repeater site is not within the IEEE standard of
120 +/- 5%, then the utility should be contacted to change the transformer
taps to bring the voltage within tolerance.

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of N9WYS
Sent: Monday, January 15, 2007 8:43 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: Switching Power Supply vs. Astron Etc.

I'd like to pose a question here regarding only a portion of the discussion.
This pertains to the "cleanliness" of the power received. I understand that
the voltage can fluctuate widely when the utility switches on and out
various circuits to meet demand.

Skipp mentions that this can cause nasty things to happen to power supplies
in equipment racks and cabinets in transmitter rooms, among other items of
equipment.

My question is this: is it worthwhile to install a variac on the mains for
the item in question to "stabilize" the voltage? Or will this not work as I
envision it might/should?

Mark - N9WYS

-Original Message-

(much text snippage) 

I'll take the turn it off when not needed/used gamble because I've 
seen first hand what can and does come down the power line quite 
a bit more often that one would expect. It's not pretty, nor is 
it clean or stable 100% of the time. Our local utility does a 
big grid switch every weekday morning about 8am and that event 
alone is a huge glitch generator. 



 






 
Yahoo! Groups Links

[Repeater-Builder] Switching Power Supply vs. Astron Etc.

[Jack Davis]

I have to wade in here!  The ferroresonant power supplies are horribly 
inefficient under light loads.  Several years ago we replaced 15 hops of tube 
type microwave with solid state.  Each repeater site had a Sola ferroresonant 
voltage regulator and they all ran slightly warm.  After we reduced the load, 
the transformers ran so hot they would cause a skin burn and actually burned 
the paint on several sites.  We ended up making a trip to remove every one of 
them to prevent a shelter fire.  The load went down and the circulating 
currents in the Sola transformers went way up.  If you have a power supply 
feeding a repeater, it is sized for the maximum transmit power demands and 
during receive time the load goes way down and guess what, the efficiency goes 
to pot!  Ferroresonant transformers can also increase the damage caused by a 
sharp rise and fall time spike.  They can actually ring and cause one spike to 
turn into a bunch of spikes with lots of energy that stresses components.

As far as overvoltage damage is concerned, that can happen on both analog and 
switchers, that is why you use a good stiff crowbar circuit to protect the 
equipment.  It is very common to have a "reach through" failure on a series 
pass transistor, where a hole gets punched between the emitter and collector 
causing a short.  This then puts the full regulator input voltage on the 
output, yet the emitter base and collector base junctions will test OK!

Don't get me wrong, I would much rather work on an  analog supply than a 
switcher!  They both have good and bad points, but sometimes the situation 
drives one into favor over the other.  I like switch mode supplies where size 
and heat are issues and I like analog supplies for the simplicity and lower 
parts count.  Ferroresonant supplies have their place, just not at my place!

Jack
K6YC

RE: [Repeater-Builder] Re: Switching Power Supply vs. Astron Etc.

[Eric Lemmon]

Mark,

Sudden and regular changes in voltage levels on long lines are normally
caused by the switching in and out of capacitor banks that are used to
improve voltage regulation on long distribution lines.  This is most
commonly used on lines carrying 4,160 to 22,000 volts.  In areas where light
industrial loads are common, the power factor is lagging during most of the
day, due to the number of motors and other inductive loads connected.  To
counteract this lagging power factor, capacitor banks are switched in and
out by either a timer or a voltage sensor.  In my area, the nominal voltage
jumped from about 119 volts to 123 volts in the morning, and dropped back in
the late afternoon.

This practice is very important in rural areas, where a 12kV line might run
20 miles to a farm.  If regulators or capacitor banks were not used to
stabilize the voltage, there would be large excursions each time the farmer
started his irrigation pumps.  Motors, being inductive, cause a lagging
power factor that results in an increased voltage drop on the distribution
circuit.  The capacitors supply capacitive reactance that cancels the
inductive reactance and, when properly applied, will improve the power
factor to near unity and minimize the voltage drop.

Most well-designed power supplies, both linear and switch-mode, will
maintain a relatively stable output voltage despite wide variations in AC
input voltage.  Some designs are nearly immune to step-voltage changes
resulting from capacitor switching.  I don't think it's necessary to employ
a Variac or similar variable transformer to adjust the voltage.  If the
measured AC voltage at the repeater site is not within the IEEE standard of
120 +/- 5%, then the utility should be contacted to change the transformer
taps to bring the voltage within tolerance.

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of N9WYS
Sent: Monday, January 15, 2007 8:43 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Re: Switching Power Supply vs. Astron Etc.

I'd like to pose a question here regarding only a portion of the discussion.
This pertains to the "cleanliness" of the power received. I understand that
the voltage can fluctuate widely when the utility switches on and out
various circuits to meet demand.

Skipp mentions that this can cause nasty things to happen to power supplies
in equipment racks and cabinets in transmitter rooms, among other items of
equipment.

My question is this: is it worthwhile to install a variac on the mains for
the item in question to "stabilize" the voltage? Or will this not work as I
envision it might/should?

Mark - N9WYS

-Original Message-

(much text snippage) 

I'll take the turn it off when not needed/used gamble because I've 
seen first hand what can and does come down the power line quite 
a bit more often that one would expect. It's not pretty, nor is 
it clean or stable 100% of the time. Our local utility does a 
big grid switch every weekday morning about 8am and that event 
alone is a huge glitch generator. 



 

RE: [Repeater-Builder] minor formula typo in formula switching power supplies

[Jeff DePolo]

> I guess I don't "get" the above statement.  I once measured the power 
> consumption of a Samlex switching power supply & my 20 amp 
> Astron linear 
> supply with an AC wattmeter & calculated that the Samlex 
> would pay for 
> itself in energy savings in 2 to 3 years.  I only continue to use the 
> Astron because it's a proven performer but will eventually 
> switch over to 
> Samlex if they continue to receive good reviews.
> 
> Bob NO6B

Bob, FWIW, my only bad experience with a switching supply was a Samlex (I
think the model was 1212 or something like that; it was rated for 12A).
Anyway, it had been working fine for several years powering a rack of about
8 rMicor eceivers, a voter, and a 5-watt link transmitter.  I had to move
the cabinet to a different location at the site, and after I did, when I
plugged the supply back in, a few seconds later I noticed smoke coming out
of the voter.  Oh boy!  I had damage to 4 receivers and the voter.  A
post-mortem on the bench later that night revealed that the power supply was
putting out about 32V.

--- Jeff

RE: [Repeater-Builder] Re: Switching Power Supply vs. Astron Etc.

[N9WYS]

I'd like to pose a question here regarding only a portion of the discussion.
This pertains to the "cleanliness" of the power received.  I understand that
the voltage can fluctuate widely when the utility switches on and out
various circuits to meet demand.

Skipp mentions that this can cause nasty things to happen to power supplies
in equipment racks and cabinets in transmitter rooms, among other items of
equipment.

My question is this: is it worthwhile to install a variac on the mains for
the item in question to "stabilize" the voltage?  Or will this not work as I
envision it might/should?

Mark - N9WYS

-Original Message-

(much text snippage) 

I'll take the turn it off when not needed/used gamble because I've 
seen first hand what can and does come down the power line quite 
a bit more often that one would expect.  It's not pretty, nor is 
it clean or stable 100% of the time.  Our local utility does a 
big grid switch every weekday morning about 8am and that event 
alone is a huge glitch generator.  

[Repeater-Builder] Re: Switching Power Supply vs. Astron Etc.

[skipp025]

(much text snip'age) 

> I agree with you!  The only difference will be any increased 
> efficiencies in the switcher over the mag and that will be small. 

"efficiencies" vs benefits? or are we calling them the same in 
this thread? 

> if the equipment that is powered by the astron, draws 30 amps, 
> it's going to draw 30 amps on the switcher. THAT CANNOT CHANGE   
> The power supply, both switcher and mag type, will draw the 
> required line current that is demanded by  that load. 

I don't see a mention of the linear regulator efficiency vs 
the switcher.  The method of Voltage regulation is the key. 
The line current drawn by the switcher will be less than the 
typical linear regulator and a lot less than many of the ferro-
resonant transformer equipped power supplies. 

> If 30 amps are required at 13.8 volts the resultant power consumed 
> will REMAIN THE SAME POWERED BY THE MAG OR SWITCHER SUPPLY. 

Not so... the linear regulator circuit will consume quite a bit 
more energy, which most often ends up as heat... hence the reason 
why we have large (often undersized) heat sinks on the sides of 
those high current Astron Supplies. 

> then the efficiency differences between the two types of supply 
> will be the ONLY POSSIBLE DECREASE IN CONSUMED ELECTRICITY.

Well... I thought that's what we were talking about... but maybe 
no soup for me.  hummm 

> Since efficiency is the ONLY POSSIBLE GAIN and the switcher cannot 
> generate electricity and there is no perpetual motion, needed 
> magnetizing current decrease and possible utility current power 
> factor improvements are the ONLY POSSIBLE IMPROVEMENTS THAT CAN 
> OCCUR. 

Are you including ferroresonant repeater power supplies in your 
above statement? 

> As you can see,  the only real advantage to the switching 
> supplies are mostly physical. 

Naaah... !  now you'r off the rails.  What about the heat 
of the linear regulator? What about the energy required to 
deal with the extra heat? What about the possible reduced life 
span of the supply because of heat issues?  What about those 
cute little hungry ferroresonant transformers found in a lot 
of Motorola Repeaters?  What about red wine with fish? 

> If anyone believes they are going to save any substantial amount 
> of money by converting to switchers, they are going to be rudely 
> awakened. 

I was nicely - rudely awakened to the savings received over a 
hungry MSR-2000 linear power supply retrofit a few years back.  
Never thought to compare the before and after...  but I can clearly 
see the difference on the utility bills I pay.  Might be something 
worth following up with some measurements next time I visit a 
site. 

> It would take decades to recoup the cost of such equipment 
> replacements based upon utility savings.

Only the actual numbers will tell the true story... There's more 
to the picture than utility savings but it is the major thread 
subject.  Also keep in mind commercial power costs more than 
home power... quite a bit where I'm located.  

> One last myth left to clear up. A power supply connected to ac 
> current and left turned on 24/7/365 is the way to insure increased 
> equipment longevity. 

Not in my book... and not based on my actual experience. 

> I have heard many people say they must "turn their power supply 
> off when equipment is not being used to save electricity."  NOTHING 
> COULD BE MORE ERRONEOUS. 

Not to save electricity... to save the supply.  If you've ever 
spent any time on the power grid with serious test equipment you'd 
probably never leave anything even plugged in (when not used) if 
you had the option.  I used to expect 100% clean power out of the 
wall and now by experience I know that expectation to be over 
optimistic. 

> The ONLY electricity being consumed when the load is switched 
> off, is magnetizing current and voltage correction current from 
> leakage etc.

What..?  you've never seen a Sola or a power supply with a ferro-
resonant transformer (aka energy soak)? 

> Once again we speak of pennies. If you consider the stress 
> caused by switching the power supply on and off many times, 
> in the end you loose. Life expectancy is decreased by in rush,  
> each time the unit is re-energized. 

But the no free lunch rule applies. You fail to mention any 
of the issues related to the larger linear supply filter caps 
and how they degrade over time with heat. If the supply is 
on, it's often warm.  If it's more than warm it's not helping 
the filter capacitors a lot. 

I'll take the turn it off when not needed/used gamble because I've 
seen first hand what can and does come down the power line quite 
a bit more often that one would expect.  It's not pretty, nor is 
it clean or stable 100% of the time.  Our local utility does a 
big grid switch every weekday morning about 8am and that event 
alone is a huge glitch generator. 

> I have had Astron mag. supplies functioning for DECADES with 
> no failure. As long as the input i

Re: [Repeater-Builder] minor formula typo in formula switching power supplies

[no6b]

At 1/15/2007 13:30, you wrote:
>Once again  Retrofit does NOT  make justifiable sense under any 
>circumstances> Do so when the unit fails. There is no contest 
>there.  Retrofit to save energy does NOT get it.

I guess I don't "get" the above statement.  I once measured the power 
consumption of a Samlex switching power supply & my 20 amp Astron linear 
supply with an AC wattmeter & calculated that the Samlex would pay for 
itself in energy savings in 2 to 3 years.  I only continue to use the 
Astron because it's a proven performer but will eventually switch over to 
Samlex if they continue to receive good reviews.

Bob NO6B

[Repeater-Builder] Re: minor formula typo in formula switching power supplies

[skipp025]

> Message Once again  Retrofit does NOT  make justifiable sense under 
> any circumstances> Do so when the unit fails. There is no contest 
> there.  Retrofit to save energy does NOT get it.

I don't agree... but my fingers are tired from yacking... so I'll 
read what other people have to say and follow up with a working 
example "that does get it." 

cheers,
skipp 

[Repeater-Builder] Motorola Module

[John]

Sorry about the first post, didn't check the subject line

John wrote:

>Anyone have any info on a Motorola module MHW561? Supply volts, 
>bandwidth, etc.
>
>Thanks,
>
>John, K4AG
>  
>

RE: [Repeater-Builder] minor formula typo in formula switching power supplies

[Paul Finch]

Eric,

You said it they way I wanted to but did not know how to say it!  When some
of those power supplies "idle" at 46 watts or MORE it makes a huge
difference when multiplied by several stations.

Paul
WB5IDM
www.AzleComm.com



-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Eric Lemmon
Sent: Monday, January 15, 2007 8:25 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] minor formula typo in formula switching
power supplies

David,

Perhaps you are not looking at the facts.  Any reduction in energy
consumption during periods when equipment is idle will reap HUGE savings.
Because this is a topic which has begat many incorrect assumptions, let's
take an example.

I put a digital wattmeter on the AC input cord of a 100W MICOR repeater
which was equipped with a TPN1106A linear power supply.  With absolutely no
load on the output of the power supply, it consumed 46 watts of power.  With
the repeater connected and in standby mode, the power consumption was just
over 50 watts.  Then, when I connected an Astron SS-25 switching power
supply, the no-load power consumption was about 7 watts.  With the repeater
in standby, it was 10 watts.

Based solely on my simple example, the linear power supply is consuming
about 438 kWh per year, at a cost of $57 per year at a rate of 13 cents per
kWh.  If I used the switching power supply, the annual energy consumption
would be about 88 kWh, at a cost of about $11.  A five-to-one energy
consumption ratio is hardly splitting hairs- it's a significant disparity!
At a crowded radio site with a heavy power load, the inefficiency can amount
to thousands of dollars per year.

My example only cites the potential savings if the repeater sits idle for an
entire year.  Ah, but the savings are also significant when the repeater is
heavily used.  While I don't have data to prove my point right now, it
should be obvious that a power supply that is inefficient when idle is not
going to become magically efficient when loaded.  Let's be charitable and
assume that the repeater is transmitting 50% of the time- this would be a
VERY heavily-used repeater!  If my energy-consumption numbers are valid, we
might use three or four times the energy with a linear supply as with a
switching supply.  I guarantee that the bean-counters within the company are
going to be looking for ways to cut back!

In my job as a power engineer for a major aerospace company, I am always
looking for ways to eliminate energy waste.  One simple way to reduce energy
costs in continuously-lighted production areas is to use #10 copper wire in
place of #12 copper wire in the 20A lighting circuits.  The energy saved in
this manner, due to reduced current-induced heating in the wiring, resulted
in amortizing the capital cost of the larger wire in just six months, with
the savings going on forever.  This is hardly splitting hairs!  (Credit the
Copper Development Association for this energy-saving idea)

73, Eric Lemmon WB6FLY


-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of DaveH
Sent: Monday, January 15, 2007 1:42 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] minor formula typo in formula switching
power supplies

Once again we are losing sight of the fact that retrofit to save energy is
just not worth it.  Replacing a failed unit, setting up new, or upgrading
all equipment , there is absolutely no contest.  At this point we are
splitting hairs.  No corporation in its right mind would justify any other
approach.
David R. Henry LME







Yahoo! Groups Links





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It's free and you'll never lose track of a phone number
again! 

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Visit http://www.ourphoneList.com";>OurPhonelist.com
It's free and you'll never lose track of a phone number 
again! 

[Repeater-Builder] CAT-1000 to Kendecom Mark 4

[Mike Besemer \(WM4B\)]

Greetings all,

Our club has 2 Kendecom Mark 4 repeaters, both of which have been lightning
struck through the phone line, but which have good receivers and
transmitters.  I've tried to make one good one from the two of them, and
have come up with one repeater which is functional as a spare for our ACS
KPR-5000, but it is not 100% operational.  I'd like to interface one of the
Mark 4's with our spare CAT-1000.  Has anybody done this who is willing to
share their interface with me.  I've looked it all over and it seems quite
do-able, but I've already got more irons in the fire then I need, so I'd
appreciate not having to reinvent the wheel.

73,

Mike
WM4B
Kathleen, GA
Central Georgia Amateur Radio Club
http://members.cox.net/cgarc

Re: [Repeater-Builder] OT; Evidence of first male engineer

[John]

Anyone have any info on a Motorola module MHW561? Supply volts, 
bandwidth, etc.

Thanks,

John, K4AG

RE: [Repeater-Builder] minor formula typo in formula switching power supplies

[Eric Lemmon]

David,

Perhaps you are not looking at the facts.  Any reduction in energy
consumption during periods when equipment is idle will reap HUGE savings.
Because this is a topic which has begat many incorrect assumptions, let's
take an example.

I put a digital wattmeter on the AC input cord of a 100W MICOR repeater
which was equipped with a TPN1106A linear power supply.  With absolutely no
load on the output of the power supply, it consumed 46 watts of power.  With
the repeater connected and in standby mode, the power consumption was just
over 50 watts.  Then, when I connected an Astron SS-25 switching power
supply, the no-load power consumption was about 7 watts.  With the repeater
in standby, it was 10 watts.

Based solely on my simple example, the linear power supply is consuming
about 438 kWh per year, at a cost of $57 per year at a rate of 13 cents per
kWh.  If I used the switching power supply, the annual energy consumption
would be about 88 kWh, at a cost of about $11.  A five-to-one energy
consumption ratio is hardly splitting hairs- it's a significant disparity!
At a crowded radio site with a heavy power load, the inefficiency can amount
to thousands of dollars per year.

My example only cites the potential savings if the repeater sits idle for an
entire year.  Ah, but the savings are also significant when the repeater is
heavily used.  While I don't have data to prove my point right now, it
should be obvious that a power supply that is inefficient when idle is not
going to become magically efficient when loaded.  Let's be charitable and
assume that the repeater is transmitting 50% of the time- this would be a
VERY heavily-used repeater!  If my energy-consumption numbers are valid, we
might use three or four times the energy with a linear supply as with a
switching supply.  I guarantee that the bean-counters within the company are
going to be looking for ways to cut back!

In my job as a power engineer for a major aerospace company, I am always
looking for ways to eliminate energy waste.  One simple way to reduce energy
costs in continuously-lighted production areas is to use #10 copper wire in
place of #12 copper wire in the 20A lighting circuits.  The energy saved in
this manner, due to reduced current-induced heating in the wiring, resulted
in amortizing the capital cost of the larger wire in just six months, with
the savings going on forever.  This is hardly splitting hairs!  (Credit the
Copper Development Association for this energy-saving idea)

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of DaveH
Sent: Monday, January 15, 2007 1:42 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] minor formula typo in formula switching
power supplies

Once again we are losing sight of the fact that retrofit to save energy is
just not worth it.  Replacing a failed unit, setting up new, or upgrading
all equipment , there is absolutely no contest.  At this point we are
splitting hairs.  No corporation in its right mind would justify any other
approach. 
David R. Henry LME

RE: [Repeater-Builder] minor formula typo in formula switching power supplies

[Paul Finch]

Again, in my case it does.  The payback would not take that long!
 
Paul
 

   _  

From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of DaveH
Sent: Monday, January 15, 2007 3:30 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] minor formula typo in formula switching
power supplies


Once again  Retrofit does NOT  make justifiable sense under any
circumstances> Do so when the unit fails. There is no contest there.
Retrofit to save energy does NOT get it.

- Original Message - 
From: HYPERLINK "mailto:[EMAIL PROTECTED]"Paul Finch 
To: HYPERLINK
"mailto:Repeater-Builder@yahoogroups.com"Repeater-Builder@yahoogroups.com 
Sent: Monday, January 15, 2007 4:01 PM
Subject: RE: [Repeater-Builder] minor formula typo in formula switching
power supplies

David,
 
True, but in a commercial application like mine where I have around 12
supplies (beside my Ham stuff) in the building it does make a difference.
One other thing you may want to consider, the tower owner that is giving you
free (or very cheap) tower space for your Ham repeaters.  I am sure he would
like any help he could get to lower his already out of site electric
charges.  I know I do!  Just offering the "other" side of the equation.
 
One other thing that has not been mentioned here, this time.  The idle
current that the Ferro-resonant supplies exhibit on the input without a load
that the switchers don't.  Every way I have looked at the problem I can't
get past that idle current even when the repeater is not on the air.  Wish
someone could explain that in a way I could understand.
 
Someone mentioned the inline AC meter the other day, the problem so far with
them is I can't put them in line with the Paging transmitters to check how
much the use per month.  Anyone know of one that has a high current setting
that reads up to 30 or 40 Amps?  Guess I will have to drag out a GE
Ferro-resonant supply and test it against on of my big switchers.
 
Paul
 

   _  

From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of DaveH
Sent: Monday, January 15, 2007 1:14 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] minor formula typo in formula switching
power supplies


Hello,
I can respect your opinion.  Taking into account that average ham radio
station has a duty cycle of 10%  or less, the figures you quote are much to
high.  This response is general information relative to normal amateur use.
As far as a single repeater running off one, most repeater systems use in
this nation has fallen off dramatically, Once again  the number you quote is
much to high. I have proven this many times over.  If, as you indicate the
load  had A duty cycle of ten hours, you observations would be correct
relative to cost if the playing field was level. . In a commercial setting
perhaps that might bear fruition. However, in a commercial setting power
factor would become a point of concern. Here the utility company becomes
concerned about power factor and keeping loads on the three phase supply in
nominal balance relative to amperage loads. 
If someone has to worry about approx $7.00 per month, there are other
issues that will indeed out weigh that. In addition, utility companies have
MINIMUM monthly charges and it is highly doubtful one would even see $7.00
savings  given the monthly bill calculated by your example is $22 and change
. Here the minimum charge utility companies have is approx $17.00 monthly
(and that is lowest).  The VERY BEST one could expect is perhaps $5.00 and
that is extremely doubtful. Using the terms decades to repay is perhaps
exaggeration. However, return on investment would not even come close to
being justifiable.
David R. Henry LME 

- Original Message - 
From: HYPERLINK "mailto:[EMAIL PROTECTED]"WYSA 
To: HYPERLINK
"mailto:Repeater-Builder@yahoogroups.com"Repeater-Builder@yahoogroups.com 
Sent: Monday, January 15, 2007 1:27 PM
Subject: RE: [Repeater-Builder] minor formula typo in formula switching
power supplies

Hi Dave,
 
I read with interest your comments.  Lets do some math to see if your
decades long pay back is correct.
 
I agree with your observation about efficiency being the only real
difference between the two types of supplies.  
So taking that input, lets see what the numbers say.
 
Typical Setup (numbers rounded to make the math easy):
 
DC Load:  14 vdc at 30 amps 
Usage:  10 hours per day, 365 days per year
Electricity cost:  10 cents per KHw
 
Setup 1:
Linear supply (ASTRON RM35 for example)
 
Looking at the schematic, the output of the transformer (into the linear
regulator circuit) is 25 volts at full load, lets say 30 amps.
The load power is 14 volts times 30 amps or 420 watts.
The power into the linear regulator is 25 volts times 30 amps or 750 watts.
Linear regulators dissipate the difference as heat...
This gives an efficiency of 56%  (420/750 *100)
Lets say the supply needs 750 watts to supply 420 watts, ignoring mag cor

Re: [Repeater-Builder] minor formula typo in formula switching power supplies

[DaveH]

MessageOnce again we are loosing sight of the fact that retrofit to save energy 
is just not worth it.  Replacing a failed unit, setting up new, or upgrading 
all equipment , there is absolutely no contest.  At this point we are splitting 
hairs.  No corporation in it's right mind would justify any other approach. 
David R. Henry LME
  - Original Message - 
  From: WYSA 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Monday, January 15, 2007 3:36 PM
  Subject: RE: [Repeater-Builder] minor formula typo in formula switching power 
supplies


  Hi Jay,

  Yes the switcher will pull less AC power from the Genset under load when 
compared to a linear supply. But the difference will depend on the load, and in 
an emergency power situation, you probably will shut off the power amp and run 
on the exciter to save energy.  This is where you would see the most pop for 
your buck.

  I've not measured the difference between the two types of supplies when under 
minimum load.  As you can tell from the numbers below, as the load current 
drops off, the advantage of the switcher in terms of dollars saved goes down.  
However, the relative efficiencies do not change until you get to the minimum 
load area.  The switcher generally needs a minimum load to operate properly, 
this is usually satisfied by the receiver if nothing else. This is where a more 
detailed design would have to be done to wring out all the performance.

  From an emergency repeater perspective, a switcher is better for its lower 
current draw.  However, the choice of radio, amplifier power, controller, 
overall package size needed, power source, etc probably drive the overall 
design.

  Take care,
  Marc


-Original Message-
From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf 
Of Jay Urish
Sent: Monday, January 15, 2007 1:48 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] minor formula typo in formula switching 
power supplies


How about the other metric? Load on th AC Mains should the grid drop and 
everything switches over to Genset.

Does the switcher pull less AC as well? With DC load and without?

WYSA wrote:
> 
> 
> Hi Dave,
> 
> I read with interest your comments. Lets do some math to see if your 
> decades long pay back is correct.
> 
> I agree with your observation about efficiency being the only real 
> difference between the two types of supplies. 
> So taking that input, lets see what the numbers say.
> 
> Typical Setup (numbers rounded to make the math easy):
> 
> DC Load: 14 vdc at 30 amps
> Usage: 10 hours per day, 365 days per year
> Electricity cost: 10 cents per KHw
> 
> Setup 1:
> Linear supply (ASTRON RM35 for example)
> 
> Looking at the schematic, the output of the transformer (into the linear 
> regulator circuit) is 25 volts at full load, lets say 30 amps.
> The load power is 14 volts times 30 amps or 420 watts.
> The power into the linear regulator is 25 volts times 30 amps or 750 
> watts. Linear regulators dissipate the difference as heat...
> This gives an efficiency of 56% (420/750 *100)
> Lets say the supply needs 750 watts to supply 420 watts, ignoring mag 
> core losses, phase, etc.
> The total yearly run time is about 3650 hours (10*365).
> Total KWh is 750*3650/1000 = 2,737 KWh per year
> Total cost is about $273 per year (10 cents * 2737 KWH).
> 
> 
> Setup 2:
> Switching power supply (General type)
> 
> Load power is again 420 watts.
> Typical efficiency is 80%. There are higher efficiency power supplies, 
> but lets use 80% for now.
> This gives an input power of 525 watts (420 / 0.8)
> Total yearly run time is again 3650 hours.
> Total KWh is 525*3650/1000 = 1,916 KWH per year
> Total cost is about $191 per year.
> 
> 
> The switcher will save you $82 per year in lower electric costs. This 
> savings is for each power supply in use, given the duty cycle above. Of 
> course, the lower your current requirements or lower duty cycle, the 
> less you save in real dollars per year. However, I do not see any 
> chance of a decades long pay back... I'll take the $82 per year savings 
> and the lower heat load in the cabinet any time. The one exception 
> might be if the room also houses or uses LF of HF communications. I'd 
> be more careful in the situation. Otherwise, why not???
> 
> Sometimes the devil is in the details. I've been a BSEE for 23 years 
> now and the smallest details can get ya. One comment about my analysis, 
> I have not taken into account power factor correction or phase angle 
> issues. Most modern switchers now come with power factor correction in 
> the AC input side. The analysis was meant to be simplistic to give the 
> reader an idea on how much efficiencies c

Re: [Repeater-Builder] minor formula typo in formula switching power supplies

[DaveH]

MessageOnce again  Retrofit does NOT  make justifiable sense under any 
circumstances> Do so when the unit fails. There is no contest there.  Retrofit 
to save energy does NOT get it.
  - Original Message - 
  From: Paul Finch 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Monday, January 15, 2007 4:01 PM
  Subject: RE: [Repeater-Builder] minor formula typo in formula switching power 
supplies


  David,

  True, but in a commercial application like mine where I have around 12 
supplies (beside my Ham stuff) in the building it does make a difference.  One 
other thing you may want to consider, the tower owner that is giving you free 
(or very cheap) tower space for your Ham repeaters.  I am sure he would like 
any help he could get to lower his already out of site electric charges.  I 
know I do!  Just offering the "other" side of the equation.

  One other thing that has not been mentioned here, this time.  The idle 
current that the Ferro-resonant supplies exhibit on the input without a load 
that the switchers don't.  Every way I have looked at the problem I can't get 
past that idle current even when the repeater is not on the air.  Wish someone 
could explain that in a way I could understand.

  Someone mentioned the inline AC meter the other day, the problem so far with 
them is I can't put them in line with the Paging transmitters to check how much 
the use per month.  Anyone know of one that has a high current setting that 
reads up to 30 or 40 Amps?  Guess I will have to drag out a GE Ferro-resonant 
supply and test it against on of my big switchers.

  Paul




--
  From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of 
DaveH
  Sent: Monday, January 15, 2007 1:14 PM
  To: Repeater-Builder@yahoogroups.com
  Subject: Re: [Repeater-Builder] minor formula typo in formula switching power 
supplies


  Hello,
  I can respect your opinion.  Taking into account that average ham radio 
station has a duty cycle of 10%  or less, the figures you quote are much to 
high.  This response is general information relative to normal amateur use.  As 
far as a single repeater running off one, most repeater systems use in  this 
nation has fallen off dramatically, Once again  the number you quote is much to 
high. I have proven this many times over.  If, as you indicate the load  had A 
duty cycle of ten hours, you observations would be correct relative to cost if 
the playing field was level. . In a commercial setting perhaps that might bear 
fruition. However, in a commercial setting power factor would become a point of 
concern. Here the utility company becomes concerned about power factor and 
keeping loads on the three phase supply in nominal balance relative to amperage 
loads. 
  If someone has to worry about approx $7.00 per month, there are other 
issues that will indeed out weigh that. In addition, utility companies have 
MINIMUM monthly charges and it is highly doubtful one would even see $7.00 
savings  given the monthly bill calculated by your example is $22 and change . 
Here the minimum charge utility companies have is approx $17.00 monthly (and 
that is lowest).  The VERY BEST one could expect is perhaps $5.00 and that is 
extremely doubtful. Using the terms decades to repay is perhaps exaggeration. 
However, return on investment would not even come close to being justifiable.
  David R. Henry LME 
- Original Message - 
From: WYSA 
To: Repeater-Builder@yahoogroups.com 
Sent: Monday, January 15, 2007 1:27 PM
Subject: RE: [Repeater-Builder] minor formula typo in formula switching 
power supplies


Hi Dave,

I read with interest your comments.  Lets do some math to see if your 
decades long pay back is correct.

I agree with your observation about efficiency being the only real 
difference between the two types of supplies.  
So taking that input, lets see what the numbers say.

Typical Setup (numbers rounded to make the math easy):

DC Load:  14 vdc at 30 amps 
Usage:  10 hours per day, 365 days per year
Electricity cost:  10 cents per KHw

Setup 1:
Linear supply (ASTRON RM35 for example)

Looking at the schematic, the output of the transformer (into the linear 
regulator circuit) is 25 volts at full load, lets say 30 amps.
The load power is 14 volts times 30 amps or 420 watts.
The power into the linear regulator is 25 volts times 30 amps or 750 watts. 
 Linear regulators dissipate the difference as heat...
This gives an efficiency of 56%  (420/750 *100)
Lets say the supply needs 750 watts to supply 420 watts, ignoring mag core 
losses, phase, etc.
The total yearly run time is about 3650 hours (10*365).
Total KWh is 750*3650/1000 = 2,737 KWh per year
Total cost is about $273 per year (10 cents * 2737 KWH).


Setup 2:
Switching power supply (General type)

Load power is again 420 wa

Re: [Repeater-Builder] minor formula typo in formula switching power supplies

[DaveH]

MessageHello again Marc,

Yes to an extent we are looking at different angles.  However, retrofiting any 
setup just for the sake of energy saving just doesn't cut it. As does turning 
off any power supply to save energy. That is in fact what instituted this 
response. To much "black box" and "snake oil"  out there!  Thanks for the good 
responses. God Bless.   73
David R. Henry LME
  - Original Message - 
  From: WYSA 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Monday, January 15, 2007 3:26 PM
  Subject: RE: [Repeater-Builder] minor formula typo in formula switching power 
supplies


  David,

  Well, being that this is the repeater group, I assumed we were discussing 
repeaters, not an average ham HF station.  Certainly, no one I know uses his HF 
radio 10 hrs a day, 7 days a week...  My mis-understanding of your e-mail.  
Anyone can certainly bend the numbers to make any point you'd like, even me.  
If you never turn them on, who cares what type of supply you have!

  In any case, I was referring to more of a commercial repeater situation or a 
busy ham situation, of which there are lots of owners/builders on this 
reflector.  Your original e-mail did not indicate any duty cycle.  Your limited 
use view is not universal and I was trying to make that point.  I believe there 
are plenty of people here who deal with high use equipment and 
multi-transmitter type sites, including hams (clubs) who run multiple repeaters 
on multiple sites.  I was simply trying to make the point that switchers are 
more efficient and cost effective, especially in a high use environment.  And 
yes, my ham club would love to save $10 a month on the electric bill (being 
hams of course!). 

  By the way, Power factor is not a problem on properly designed modern 
switching power supplies.

  You keep saying return on investment.  In my industry, switching power 
supplies do not significantly cost more than linears (new vs new), so my only 
guess is you are referring to taking working linears out of service to be 
replaced with switchers, just to save money. (Ignoring heat load and size 
savings) Is this correct?  If not, there is no significant difference on 
investment, so I'm confused as to what you mean by return on investment in this 
case.  And if this is a new installation, why put in equipment which draws more 
power than needed, is larger, and produces more heat under load?  (Again, for a 
VHF/UHF repeater situation, not an HF station in your basement).


  Thanks for the discussion! I guess we are approaching this from two different 
angles.  

  Take care,
  Marc




-Original Message-
From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf 
Of DaveH
Sent: Monday, January 15, 2007 2:14 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] minor formula typo in formula switching 
power supplies

Hello,
I can respect your opinion.  Taking into account that average ham radio 
station has a duty cycle of 10%  or less, the figures you quote are much to 
high.  This response is general information relative to normal amateur use.  As 
far as a single repeater running off one, most repeater systems use in  this 
nation has fallen off dramatically, Once again  the number you quote is much to 
high. I have proven this many times over.  If, as you indicate the load  had A 
duty cycle of ten hours, you observations would be correct relative to cost if 
the playing field was level. . In a commercial setting perhaps that might bear 
fruition. However, in a commercial setting power factor would become a point of 
concern. Here the utility company becomes concerned about power factor and 
keeping loads on the three phase supply in nominal balance relative to amperage 
loads. 
If someone has to worry about approx $7.00 per month, there are other 
issues that will indeed out weigh that. In addition, utility companies have 
MINIMUM monthly charges and it is highly doubtful one would even see $7.00 
savings  given the monthly bill calculated by your example is $22 and change . 
Here the minimum charge utility companies have is approx $17.00 monthly (and 
that is lowest).  The VERY BEST one could expect is perhaps $5.00 and that is 
extremely doubtful. Using the terms decades to repay is perhaps exaggeration. 
However, return on investment would not even come close to being justifiable.
David R. Henry LME 
 

   

Re: [Repeater-Builder] minor formula typo in formula switching power supplies

[w5zit]

Keep in mind that the current times voltage measured on the input of a 
ferro resonate power supply does not represent real power. The current 
is not in phase with the voltage, and the ferro resonate supply returns 
a lot of the current to the source so this power is not dissipated in 
the supply or its output load.

This is the same phenomenon that the power company combats when it 
places a bank of capacitors on a power pole connected across the power 
line. They are trying to correct the voltage/current phase to try to 
keep the power factor as close to 1 as they can. Any deviation from 1 
means that the extra current flowing on the power line causes extra 
power loss in the resistance of the line, and also means that the power 
line cannot carry the same load as it would with the power factor at 1.

The ferro resonant supplies do not have a regulator on the output like 
a normal linear supply - so there is no drop across a regulator to 
cause extra dissipation in the power supply. Very good efficiencies can 
be obtained with a ferro resonant supply - with acceptable regulation.

73 - Jim W5ZIT

-Original Message-
From: [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Mon, 15 Jan 2007 3:01 PM
Subject: RE: [Repeater-Builder] minor formula typo in formula switching 
power supplies

One other thing that has not been mentioned here, this time.  The idle 
current that the Ferro-resonant supplies exhibit on the input without a 
load that the switchers don't.  Every way I have looked at the problem 
I can't get past that idle current even when the repeater is not on the 
air.  Wish someone could explain that in a way I could understand.

Paul



Check Out the new free AIM(R) Mail -- 2 GB of storage and 
industry-leading spam and email virus protection.

[Repeater-Builder] Micor Base Station Amp Problem

[Laryn Lohman]

Hi all, I have a base station that came with a TLE1703 amp. It was a
part of Medcom equipment at a local hospital. I took it out of
storage last week, and it keyed up fine, with about 40 watts out. I
also have a TLE1713 amp from another station, and after quickly
swapping it with the 1703, it too seemed fine with about 70 watts out.

After moving things around in the cabinet last nite, and having the
1713 amp installed, I noticed an arcing noise from the amp. Keying
the amp with the cover off revealed arcing at random places near the
negative DC bus, and the 4.7uf capacitors getting very hot. Since
this amp shows evidence of being serviced at some point, I decided to
move back to the original 1703 amp. This amp is very clean inside and
shows no evidence of ever being serviced. This amp too will arc with
the capacitors getting very hot after only a few seconds of keydown.

So what could be the problem. I am using a good wattmeter and load.
Is there something in the antenna network after the amp that could be
bad?  I measured the SWR looking into the antenna network with the
load on the other end and it shows 2.1:1. Isn't that a little high?? 
Or maybe the caps are simply old and dried out?

Where do I look for the problem?

Laryn K8TVZ

RE: [Repeater-Builder] minor formula typo in formula switching power supplies

[WYSA]

Hi Jay,
 
Yes the switcher will pull less AC power from the Genset under load when
compared to a linear supply. But the difference will depend on the load, and
in an emergency power situation, you probably will shut off the power amp
and run on the exciter to save energy.  This is where you would see the most
pop for your buck.
 
I've not measured the difference between the two types of supplies when
under minimum load.  As you can tell from the numbers below, as the load
current drops off, the advantage of the switcher in terms of dollars saved
goes down.  However, the relative efficiencies do not change until you get
to the minimum load area.  The switcher generally needs a minimum load to
operate properly, this is usually satisfied by the receiver if nothing else.
This is where a more detailed design would have to be done to wring out all
the performance.
 
>From an emergency repeater perspective, a switcher is better for its lower
current draw.  However, the choice of radio, amplifier power, controller,
overall package size needed, power source, etc probably drive the overall
design.
 
Take care,
Marc
 
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of Jay Urish
Sent: Monday, January 15, 2007 1:48 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] minor formula typo in formula switching
power supplies



How about the other metric? Load on th AC Mains should the grid drop and 
everything switches over to Genset.

Does the switcher pull less AC as well? With DC load and without?

WYSA wrote:
> 
> 
> Hi Dave,
> 
> I read with interest your comments. Lets do some math to see if your 
> decades long pay back is correct.
> 
> I agree with your observation about efficiency being the only real 
> difference between the two types of supplies. 
> So taking that input, lets see what the numbers say.
> 
> Typical Setup (numbers rounded to make the math easy):
> 
> DC Load: 14 vdc at 30 amps
> Usage: 10 hours per day, 365 days per year
> Electricity cost: 10 cents per KHw
> 
> Setup 1:
> Linear supply (ASTRON RM35 for example)
> 
> Looking at the schematic, the output of the transformer (into the linear 
> regulator circuit) is 25 volts at full load, lets say 30 amps.
> The load power is 14 volts times 30 amps or 420 watts.
> The power into the linear regulator is 25 volts times 30 amps or 750 
> watts. Linear regulators dissipate the difference as heat...
> This gives an efficiency of 56% (420/750 *100)
> Lets say the supply needs 750 watts to supply 420 watts, ignoring mag 
> core losses, phase, etc.
> The total yearly run time is about 3650 hours (10*365).
> Total KWh is 750*3650/1000 = 2,737 KWh per year
> Total cost is about $273 per year (10 cents * 2737 KWH).
> 
> 
> Setup 2:
> Switching power supply (General type)
> 
> Load power is again 420 watts.
> Typical efficiency is 80%. There are higher efficiency power supplies, 
> but lets use 80% for now.
> This gives an input power of 525 watts (420 / 0.8)
> Total yearly run time is again 3650 hours.
> Total KWh is 525*3650/1000 = 1,916 KWH per year
> Total cost is about $191 per year.
> 
> 
> The switcher will save you $82 per year in lower electric costs. This 
> savings is for each power supply in use, given the duty cycle above. Of 
> course, the lower your current requirements or lower duty cycle, the 
> less you save in real dollars per year. However, I do not see any 
> chance of a decades long pay back... I'll take the $82 per year savings 
> and the lower heat load in the cabinet any time. The one exception 
> might be if the room also houses or uses LF of HF communications. I'd 
> be more careful in the situation. Otherwise, why not???
> 
> Sometimes the devil is in the details. I've been a BSEE for 23 years 
> now and the smallest details can get ya. One comment about my analysis, 
> I have not taken into account power factor correction or phase angle 
> issues. Most modern switchers now come with power factor correction in 
> the AC input side. The analysis was meant to be simplistic to give the 
> reader an idea on how much efficiencies can affect situations. YMMV and 
> other such sayings...
> 
> Hope this helps someone,
> Marc
> 
> 
> 
> 
> -Original Message-
> *From:* Repeater-Builder@ 
yahoogroups.com
> [mailto:Repeater-Builder@ 
yahoogroups.com] *On Behalf Of *DaveH
> *Sent:* Monday, January 15, 2007 8:41 AM
> *To:* Repeater-Builder@ 
yahoogroups.com
> *Subject:* [Repeater-Builder] minor formula typo in formula
> switching power supplies
> 
> A minor formula exists in the P=EI formula in the original message. The
> corrected version is below. To many annoying phone calls! Sorry
> about that!
> Dave
> - Original Message -
> From: "DaveH" <[EMAIL PROTECTED]  com
>
> To: ma

RE: [Repeater-Builder] minor formula typo in formula switching power supplies

[Paul Finch]

David,
 
True, but in a commercial application like mine where I have around 12
supplies (beside my Ham stuff) in the building it does make a difference.
One other thing you may want to consider, the tower owner that is giving you
free (or very cheap) tower space for your Ham repeaters.  I am sure he would
like any help he could get to lower his already out of site electric
charges.  I know I do!  Just offering the "other" side of the equation.
 
One other thing that has not been mentioned here, this time.  The idle
current that the Ferro-resonant supplies exhibit on the input without a load
that the switchers don't.  Every way I have looked at the problem I can't
get past that idle current even when the repeater is not on the air.  Wish
someone could explain that in a way I could understand.
 
Someone mentioned the inline AC meter the other day, the problem so far with
them is I can't put them in line with the Paging transmitters to check how
much the use per month.  Anyone know of one that has a high current setting
that reads up to 30 or 40 Amps?  Guess I will have to drag out a GE
Ferro-resonant supply and test it against on of my big switchers.
 
Paul
 

   _  

From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of DaveH
Sent: Monday, January 15, 2007 1:14 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] minor formula typo in formula switching
power supplies


Hello,
I can respect your opinion.  Taking into account that average ham radio
station has a duty cycle of 10%  or less, the figures you quote are much to
high.  This response is general information relative to normal amateur use.
As far as a single repeater running off one, most repeater systems use in
this nation has fallen off dramatically, Once again  the number you quote is
much to high. I have proven this many times over.  If, as you indicate the
load  had A duty cycle of ten hours, you observations would be correct
relative to cost if the playing field was level. . In a commercial setting
perhaps that might bear fruition. However, in a commercial setting power
factor would become a point of concern. Here the utility company becomes
concerned about power factor and keeping loads on the three phase supply in
nominal balance relative to amperage loads. 
If someone has to worry about approx $7.00 per month, there are other
issues that will indeed out weigh that. In addition, utility companies have
MINIMUM monthly charges and it is highly doubtful one would even see $7.00
savings  given the monthly bill calculated by your example is $22 and change
. Here the minimum charge utility companies have is approx $17.00 monthly
(and that is lowest).  The VERY BEST one could expect is perhaps $5.00 and
that is extremely doubtful. Using the terms decades to repay is perhaps
exaggeration. However, return on investment would not even come close to
being justifiable.
David R. Henry LME 

- Original Message - 
From: HYPERLINK "mailto:[EMAIL PROTECTED]"WYSA 
To: HYPERLINK
"mailto:Repeater-Builder@yahoogroups.com"Repeater-Builder@yahoogroups.com 
Sent: Monday, January 15, 2007 1:27 PM
Subject: RE: [Repeater-Builder] minor formula typo in formula switching
power supplies

Hi Dave,
 
I read with interest your comments.  Lets do some math to see if your
decades long pay back is correct.
 
I agree with your observation about efficiency being the only real
difference between the two types of supplies.  
So taking that input, lets see what the numbers say.
 
Typical Setup (numbers rounded to make the math easy):
 
DC Load:  14 vdc at 30 amps 
Usage:  10 hours per day, 365 days per year
Electricity cost:  10 cents per KHw
 
Setup 1:
Linear supply (ASTRON RM35 for example)
 
Looking at the schematic, the output of the transformer (into the linear
regulator circuit) is 25 volts at full load, lets say 30 amps.
The load power is 14 volts times 30 amps or 420 watts.
The power into the linear regulator is 25 volts times 30 amps or 750 watts.
Linear regulators dissipate the difference as heat...
This gives an efficiency of 56%  (420/750 *100)
Lets say the supply needs 750 watts to supply 420 watts, ignoring mag core
losses, phase, etc.
The total yearly run time is about 3650 hours (10*365).
Total KWh is 750*3650/1000 = 2,737 KWh per year
Total cost is about $273 per year (10 cents * 2737 KWH).
 
 
Setup 2:
Switching power supply (General type)
 
Load power is again 420 watts.
Typical efficiency is 80%.  There are higher efficiency power supplies, but
lets use 80% for now.
This gives an input power of 525 watts (420 / 0.8)
Total yearly run time is again 3650 hours.
Total KWh is 525*3650/1000 = 1,916 KWH  per year
Total cost is about $191 per year.
 
 
The switcher will save you $82 per year in lower electric costs.  This
savings is for each power supply in use, given the duty cycle above.  Of
course, the lower your current requirements or lower duty cycle, the less
you save in real dollars per year.  However, I 

Re: [Repeater-Builder] minor formula typo in formula switching power supplies

[DaveH]

I'm not sure of what you are asking. Line current on genset is not going to 
be any less than on normal utility power. Line is line  no matter what. I 
sure don't understand your reference to metric?   Power is power. If perhaps 
you had a large commercial site, this would have to be considered. However, 
it would take conversion of a number of power supplies to become a real 
significant issue.  Lighting, heating, air-conditioning, and power to "other 
equipment" far outweigh this.
- Original Message - 
From: "Jay Urish" <[EMAIL PROTECTED]>
To: 
Sent: Monday, January 15, 2007 1:48 PM
Subject: Re: [Repeater-Builder] minor formula typo in formula switching 
power supplies


> How about the other metric? Load on th AC Mains should the grid drop and
> everything switches over to Genset.
>
> Does the switcher pull less AC as well? With DC load and without?
>
> WYSA wrote:
>>
>>
>> Hi Dave,
>>
>> I read with interest your comments.  Lets do some math to see if your
>> decades long pay back is correct.
>>
>> I agree with your observation about efficiency being the only real
>> difference between the two types of supplies.
>> So taking that input, lets see what the numbers say.
>>
>> Typical Setup (numbers rounded to make the math easy):
>>
>> DC Load:  14 vdc at 30 amps
>> Usage:  10 hours per day, 365 days per year
>> Electricity cost:  10 cents per KHw
>>
>> Setup 1:
>> Linear supply (ASTRON RM35 for example)
>>
>> Looking at the schematic, the output of the transformer (into the linear
>> regulator circuit) is 25 volts at full load, lets say 30 amps.
>> The load power is 14 volts times 30 amps or 420 watts.
>> The power into the linear regulator is 25 volts times 30 amps or 750
>> watts.  Linear regulators dissipate the difference as heat...
>> This gives an efficiency of 56%  (420/750 *100)
>> Lets say the supply needs 750 watts to supply 420 watts, ignoring mag
>> core losses, phase, etc.
>> The total yearly run time is about 3650 hours (10*365).
>> Total KWh is 750*3650/1000 = 2,737 KWh per year
>> Total cost is about $273 per year (10 cents * 2737 KWH).
>>
>>
>> Setup 2:
>> Switching power supply (General type)
>>
>> Load power is again 420 watts.
>> Typical efficiency is 80%.  There are higher efficiency power supplies,
>> but lets use 80% for now.
>> This gives an input power of 525 watts (420 / 0.8)
>> Total yearly run time is again 3650 hours.
>> Total KWh is 525*3650/1000 = 1,916 KWH  per year
>> Total cost is about $191 per year.
>>
>>
>> The switcher will save you $82 per year in lower electric costs.  This
>> savings is for each power supply in use, given the duty cycle above.  Of
>> course, the lower your current requirements or lower duty cycle, the
>> less you save in real dollars per year.  However, I do not see any
>> chance of a decades long pay back...  I'll take the $82 per year savings
>> and the lower heat load in the cabinet any time.  The one exception
>> might be if the room also houses or uses LF of HF communications.  I'd
>> be more careful in the situation.  Otherwise, why not???
>>
>> Sometimes the devil is in the details.  I've been a BSEE for 23 years
>> now and the smallest details can get ya.  One comment about my analysis,
>> I have not taken into account power factor correction or phase angle
>> issues.  Most modern switchers now come with power factor correction in
>> the AC input side.  The analysis was meant to be simplistic to give the
>> reader an idea on how much efficiencies can affect situations.  YMMV and
>> other such sayings...
>>
>> Hope this helps someone,
>> Marc
>>
>>
>>
>>
>> -Original Message-
>> *From:* Repeater-Builder@yahoogroups.com
>> [mailto:[EMAIL PROTECTED] *On Behalf Of *DaveH
>> *Sent:* Monday, January 15, 2007 8:41 AM
>> *To:* Repeater-Builder@yahoogroups.com
>> *Subject:* [Repeater-Builder] minor formula typo in formula
>> switching power supplies
>>
>> A minor formula exists in the P=EI formula in the original message. 
>> The
>> corrected version is below. To many annoying phone calls! Sorry
>> about that!
>> Dave
>> - Original Message -
>> From: "DaveH" <[EMAIL PROTECTED] >
>> To: > >
>> Sent: Sunday, January 14, 2007 6:27 PM
>> Subject: Re: [Repeater-Builder] Re: Switching Power Supply vs.
>> Astron Etc.
>>
>>  > Erick,
>>  > I agree with you! The only difference will be any increased
>>  > efficiencies in the switcher over the mag and that will be small.
>> I have
>>  > had
>>  > a Master Electrical License for 38 years. A physical law of
>> science says
>>  > that 746 watts equal 1 horsepower> There is no deviation from that
>>  > scientific fact. In addition, if the equipment that is powered by 
>> the
>>  > astron, draws 30 amps, it's going to draw 30 amps on the
>> switcher. THAT
>>  > CANNOT CHANGE> The power supply, both swit

RE: [Repeater-Builder] minor formula typo in formula switching power supplies

[WYSA]

David,
 
Well, being that this is the repeater group, I assumed we were discussing
repeaters, not an average ham HF station.  Certainly, no one I know uses his
HF radio 10 hrs a day, 7 days a week...  My mis-understanding of your
e-mail.  Anyone can certainly bend the numbers to make any point you'd like,
even me.  If you never turn them on, who cares what type of supply you have!
 
In any case, I was referring to more of a commercial repeater situation or a
busy ham situation, of which there are lots of owners/builders on this
reflector.  Your original e-mail did not indicate any duty cycle.  Your
limited use view is not universal and I was trying to make that point.  I
believe there are plenty of people here who deal with high use equipment and
multi-transmitter type sites, including hams (clubs) who run multiple
repeaters on multiple sites.  I was simply trying to make the point that
switchers are more efficient and cost effective, especially in a high use
environment.  And yes, my ham club would love to save $10 a month on the
electric bill (being hams of course!). 
 
By the way, Power factor is not a problem on properly designed modern
switching power supplies.
 
You keep saying return on investment.  In my industry, switching power
supplies do not significantly cost more than linears (new vs new), so my
only guess is you are referring to taking working linears out of service to
be replaced with switchers, just to save money. (Ignoring heat load and size
savings) Is this correct?  If not, there is no significant difference on
investment, so I'm confused as to what you mean by return on investment in
this case.  And if this is a new installation, why put in equipment which
draws more power than needed, is larger, and produces more heat under load?
(Again, for a VHF/UHF repeater situation, not an HF station in your
basement).
 
 
Thanks for the discussion! I guess we are approaching this from two
different angles.  
 
Take care,
Marc
 
 
 
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of DaveH
Sent: Monday, January 15, 2007 2:14 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] minor formula typo in formula switching
power supplies

Hello,
I can respect your opinion.  Taking into account that average ham radio
station has a duty cycle of 10%  or less, the figures you quote are much to
high.  This response is general information relative to normal amateur use.
As far as a single repeater running off one, most repeater systems use in
this nation has fallen off dramatically, Once again  the number you quote is
much to high. I have proven this many times over.  If, as you indicate the
load  had A duty cycle of ten hours, you observations would be correct
relative to cost if the playing field was level. . In a commercial setting
perhaps that might bear fruition. However, in a commercial setting power
factor would become a point of concern. Here the utility company becomes
concerned about power factor and keeping loads on the three phase supply in
nominal balance relative to amperage loads. 
If someone has to worry about approx $7.00 per month, there are other
issues that will indeed out weigh that. In addition, utility companies have
MINIMUM monthly charges and it is highly doubtful one would even see $7.00
savings  given the monthly bill calculated by your example is $22 and change
. Here the minimum charge utility companies have is approx $17.00 monthly
(and that is lowest).  The VERY BEST one could expect is perhaps $5.00 and
that is extremely doubtful. Using the terms decades to repay is perhaps
exaggeration. However, return on investment would not even come close to
being justifiable.
David R. Henry LME 
 
 
 

Re: [Repeater-Builder] minor formula typo in formula switching power supplies

[DaveH]

MessageHello,
I can respect your opinion.  Taking into account that average ham radio station 
has a duty cycle of 10%  or less, the figures you quote are much to high.  This 
response is general information relative to normal amateur use.  As far as a 
single repeater running off one, most repeater systems use in  this nation has 
fallen off dramatically, Once again  the number you quote is much to high. I 
have proven this many times over.  If, as you indicate the load  had A duty 
cycle of ten hours, you observations would be correct relative to cost if the 
playing field was level. . In a commercial setting perhaps that might bear 
fruition. However, in a commercial setting power factor would become a point of 
concern. Here the utility company becomes concerned about power factor and 
keeping loads on the three phase supply in nominal balance relative to amperage 
loads. 
If someone has to worry about approx $7.00 per month, there are other 
issues that will indeed out weigh that. In addition, utility companies have 
MINIMUM monthly charges and it is highly doubtful one would even see $7.00 
savings  given the monthly bill calculated by your example is $22 and change . 
Here the minimum charge utility companies have is approx $17.00 monthly (and 
that is lowest).  The VERY BEST one could expect is perhaps $5.00 and that is 
extremely doubtful. Using the terms decades to repay is perhaps exaggeration. 
However, return on investment would not even come close to being justifiable.
David R. Henry LME 
  - Original Message - 
  From: WYSA 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Monday, January 15, 2007 1:27 PM
  Subject: RE: [Repeater-Builder] minor formula typo in formula switching power 
supplies


  Hi Dave,

  I read with interest your comments.  Lets do some math to see if your decades 
long pay back is correct.

  I agree with your observation about efficiency being the only real difference 
between the two types of supplies.  
  So taking that input, lets see what the numbers say.

  Typical Setup (numbers rounded to make the math easy):

  DC Load:  14 vdc at 30 amps 
  Usage:  10 hours per day, 365 days per year
  Electricity cost:  10 cents per KHw

  Setup 1:
  Linear supply (ASTRON RM35 for example)

  Looking at the schematic, the output of the transformer (into the linear 
regulator circuit) is 25 volts at full load, lets say 30 amps.
  The load power is 14 volts times 30 amps or 420 watts.
  The power into the linear regulator is 25 volts times 30 amps or 750 watts.  
Linear regulators dissipate the difference as heat...
  This gives an efficiency of 56%  (420/750 *100)
  Lets say the supply needs 750 watts to supply 420 watts, ignoring mag core 
losses, phase, etc.
  The total yearly run time is about 3650 hours (10*365).
  Total KWh is 750*3650/1000 = 2,737 KWh per year
  Total cost is about $273 per year (10 cents * 2737 KWH).


  Setup 2:
  Switching power supply (General type)

  Load power is again 420 watts.
  Typical efficiency is 80%.  There are higher efficiency power supplies, but 
lets use 80% for now.
  This gives an input power of 525 watts (420 / 0.8)
  Total yearly run time is again 3650 hours.
  Total KWh is 525*3650/1000 = 1,916 KWH  per year
  Total cost is about $191 per year.


  The switcher will save you $82 per year in lower electric costs.  This 
savings is for each power supply in use, given the duty cycle above.  Of 
course, the lower your current requirements or lower duty cycle, the less you 
save in real dollars per year.  However, I do not see any chance of a decades 
long pay back...  I'll take the $82 per year savings and the lower heat load in 
the cabinet any time.  The one exception might be if the room also houses or 
uses LF of HF communications.  I'd be more careful in the situation.  
Otherwise, why not???

  Sometimes the devil is in the details.  I've been a BSEE for 23 years now and 
the smallest details can get ya.  One comment about my analysis, I have not 
taken into account power factor correction or phase angle issues.  Most modern 
switchers now come with power factor correction in the AC input side.  The 
analysis was meant to be simplistic to give the reader an idea on how much 
efficiencies can affect situations.  YMMV and other such sayings...

  Hope this helps someone,
  Marc



-Original Message-
From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf 
Of DaveH
Sent: Monday, January 15, 2007 8:41 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] minor formula typo in formula switching power 
supplies


A minor formula exists in the P=EI formula in the original message. The 
corrected version is below. To many annoying phone calls! Sorry about that!
Dave
- Original Message - 
From: "DaveH" <[EMAIL PROTECTED]>
To: 
Sent: Sunday, January 14, 2007 6:27 PM
Subject: Re: [Repeater-Builder] Re: Switching Power Supply vs.

Re: [Repeater-Builder] minor formula typo in formula switching power supplies

[Jay Urish]

How about the other metric? Load on th AC Mains should the grid drop and 
everything switches over to Genset.

Does the switcher pull less AC as well? With DC load and without?

WYSA wrote:
> 
> 
> Hi Dave,
>  
> I read with interest your comments.  Lets do some math to see if your 
> decades long pay back is correct.
>  
> I agree with your observation about efficiency being the only real 
> difference between the two types of supplies. 
> So taking that input, lets see what the numbers say.
>  
> Typical Setup (numbers rounded to make the math easy):
>  
> DC Load:  14 vdc at 30 amps
> Usage:  10 hours per day, 365 days per year
> Electricity cost:  10 cents per KHw
>  
> Setup 1:
> Linear supply (ASTRON RM35 for example)
>  
> Looking at the schematic, the output of the transformer (into the linear 
> regulator circuit) is 25 volts at full load, lets say 30 amps.
> The load power is 14 volts times 30 amps or 420 watts.
> The power into the linear regulator is 25 volts times 30 amps or 750 
> watts.  Linear regulators dissipate the difference as heat...
> This gives an efficiency of 56%  (420/750 *100)
> Lets say the supply needs 750 watts to supply 420 watts, ignoring mag 
> core losses, phase, etc.
> The total yearly run time is about 3650 hours (10*365).
> Total KWh is 750*3650/1000 = 2,737 KWh per year
> Total cost is about $273 per year (10 cents * 2737 KWH).
>  
>  
> Setup 2:
> Switching power supply (General type)
>  
> Load power is again 420 watts.
> Typical efficiency is 80%.  There are higher efficiency power supplies, 
> but lets use 80% for now.
> This gives an input power of 525 watts (420 / 0.8)
> Total yearly run time is again 3650 hours.
> Total KWh is 525*3650/1000 = 1,916 KWH  per year
> Total cost is about $191 per year.
>  
>  
> The switcher will save you $82 per year in lower electric costs.  This 
> savings is for each power supply in use, given the duty cycle above.  Of 
> course, the lower your current requirements or lower duty cycle, the 
> less you save in real dollars per year.  However, I do not see any 
> chance of a decades long pay back...  I'll take the $82 per year savings 
> and the lower heat load in the cabinet any time.  The one exception 
> might be if the room also houses or uses LF of HF communications.  I'd 
> be more careful in the situation.  Otherwise, why not???
>  
> Sometimes the devil is in the details.  I've been a BSEE for 23 years 
> now and the smallest details can get ya.  One comment about my analysis, 
> I have not taken into account power factor correction or phase angle 
> issues.  Most modern switchers now come with power factor correction in 
> the AC input side.  The analysis was meant to be simplistic to give the 
> reader an idea on how much efficiencies can affect situations.  YMMV and 
> other such sayings...
>  
> Hope this helps someone,
> Marc
>  
>  
>  
> 
> -Original Message-
> *From:* Repeater-Builder@yahoogroups.com
> [mailto:[EMAIL PROTECTED] *On Behalf Of *DaveH
> *Sent:* Monday, January 15, 2007 8:41 AM
> *To:* Repeater-Builder@yahoogroups.com
> *Subject:* [Repeater-Builder] minor formula typo in formula
> switching power supplies
> 
> A minor formula exists in the P=EI formula in the original message. The
> corrected version is below. To many annoying phone calls! Sorry
> about that!
> Dave
> - Original Message -
> From: "DaveH" <[EMAIL PROTECTED] >
> To:  >
> Sent: Sunday, January 14, 2007 6:27 PM
> Subject: Re: [Repeater-Builder] Re: Switching Power Supply vs.
> Astron Etc.
> 
>  > Erick,
>  > I agree with you! The only difference will be any increased
>  > efficiencies in the switcher over the mag and that will be small.
> I have
>  > had
>  > a Master Electrical License for 38 years. A physical law of
> science says
>  > that 746 watts equal 1 horsepower> There is no deviation from that
>  > scientific fact. In addition, if the equipment that is powered by the
>  > astron, draws 30 amps, it's going to draw 30 amps on the
> switcher. THAT
>  > CANNOT CHANGE> The power supply, both switcher and mag type, will
> draw
>  > the
>  > required line current that is demanded by that load. Ohm's law
> says P=EI
>  > (power ((wattage)) = E((voltage)) multiplied by the amperage
> ((I)). If 30
>  > amps
>  > are required at 13.8 volts the resultant power consumed will
> REMAIN THE
>  > SAME POWERED BY THE MAG OR SWITCHER SUPPLY. Since this physical
> law cannot
>  > change, then the efficiency differences between the two types of
> supply
>  > will
>  > be the ONLY POSSIBLE DECREASE IN CONSUMED ELECTRICITY.
>  > Since efficiency is the ONLY POSSIBLE GAIN and the switcher cannot
>  > generate electricity and there is no perpetual motion, needed
> magnetizing
>   

[Repeater-Builder] Re: AEA Isopole, Forwarded opinion on performance.

[Bathgate, Ed]

I was offered several for free,  both 2m and 220 versions that had been
tried at a repeater site.
It was claimed that these antennas have an up-tilt to the pattern,  and if
you have a high rpt site,
They overshoot your users in the valleys.   If you are down in the valley
trying to hit higher sites,
They work quite well.

$.02

Ed Bathgate
Manufacturing Test Engineer
Marconi division of Ericsson
4000 Marconi Drive
Warrendale PA 15086-7594
(724) 742-6575
Fax (724) 742-7177

RE: [Repeater-Builder] minor formula typo in formula switching power supplies

[WYSA]

Hi Dave,
 
I read with interest your comments.  Lets do some math to see if your
decades long pay back is correct.
 
I agree with your observation about efficiency being the only real
difference between the two types of supplies.  
So taking that input, lets see what the numbers say.
 
Typical Setup (numbers rounded to make the math easy):
 
DC Load:  14 vdc at 30 amps 
Usage:  10 hours per day, 365 days per year
Electricity cost:  10 cents per KHw
 
Setup 1:
Linear supply (ASTRON RM35 for example)
 
Looking at the schematic, the output of the transformer (into the linear
regulator circuit) is 25 volts at full load, lets say 30 amps.
The load power is 14 volts times 30 amps or 420 watts.
The power into the linear regulator is 25 volts times 30 amps or 750 watts.
Linear regulators dissipate the difference as heat...
This gives an efficiency of 56%  (420/750 *100)
Lets say the supply needs 750 watts to supply 420 watts, ignoring mag core
losses, phase, etc.
The total yearly run time is about 3650 hours (10*365).
Total KWh is 750*3650/1000 = 2,737 KWh per year
Total cost is about $273 per year (10 cents * 2737 KWH).
 
 
Setup 2:
Switching power supply (General type)
 
Load power is again 420 watts.
Typical efficiency is 80%.  There are higher efficiency power supplies, but
lets use 80% for now.
This gives an input power of 525 watts (420 / 0.8)
Total yearly run time is again 3650 hours.
Total KWh is 525*3650/1000 = 1,916 KWH  per year
Total cost is about $191 per year.
 
 
The switcher will save you $82 per year in lower electric costs.  This
savings is for each power supply in use, given the duty cycle above.  Of
course, the lower your current requirements or lower duty cycle, the less
you save in real dollars per year.  However, I do not see any chance of a
decades long pay back...  I'll take the $82 per year savings and the lower
heat load in the cabinet any time.  The one exception might be if the room
also houses or uses LF of HF communications.  I'd be more careful in the
situation.  Otherwise, why not???
 
Sometimes the devil is in the details.  I've been a BSEE for 23 years now
and the smallest details can get ya.  One comment about my analysis, I have
not taken into account power factor correction or phase angle issues.  Most
modern switchers now come with power factor correction in the AC input side.
The analysis was meant to be simplistic to give the reader an idea on how
much efficiencies can affect situations.  YMMV and other such sayings...
 
Hope this helps someone,
Marc
 
 
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:[EMAIL PROTECTED] On Behalf Of DaveH
Sent: Monday, January 15, 2007 8:41 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] minor formula typo in formula switching power
supplies



A minor formula exists in the P=EI formula in the original message. The 
corrected version is below. To many annoying phone calls! Sorry about that!
Dave
- Original Message - 
From: "DaveH" <[EMAIL PROTECTED]  com>
To: mailto:Repeater-Builder%40yahoogroups.com>
yahoogroups.com>
Sent: Sunday, January 14, 2007 6:27 PM
Subject: Re: [Repeater-Builder] Re: Switching Power Supply vs. Astron Etc.

> Erick,
> I agree with you! The only difference will be any increased
> efficiencies in the switcher over the mag and that will be small. I have 
> had
> a Master Electrical License for 38 years. A physical law of science says
> that 746 watts equal 1 horsepower> There is no deviation from that
> scientific fact. In addition, if the equipment that is powered by the
> astron, draws 30 amps, it's going to draw 30 amps on the switcher. THAT
> CANNOT CHANGE> The power supply, both switcher and mag type, will draw 
> the
> required line current that is demanded by that load. Ohm's law says P=EI
> (power ((wattage)) = E((voltage)) multiplied by the amperage ((I)). If 30 
> amps
> are required at 13.8 volts the resultant power consumed will REMAIN THE
> SAME POWERED BY THE MAG OR SWITCHER SUPPLY. Since this physical law cannot
> change, then the efficiency differences between the two types of supply 
> will
> be the ONLY POSSIBLE DECREASE IN CONSUMED ELECTRICITY.
> Since efficiency is the ONLY POSSIBLE GAIN and the switcher cannot
> generate electricity and there is no perpetual motion, needed magnetizing
> current decrease and possible utility current power factor improvements 
> are
> the ONLY POSSIBLE IMPROVEMENTS THAT CAN OCCUR. If you consider these 
> facts,
> you will instantly see that utility cost reductions will be minimal at 
> best.
> Electrical company power charges are calculated in KWH (kilowatt hours).
> That is calculated by the formula KHW (killer what hours ((hi hi)) =
> wattage load (both apparent and actual) multiplied by the time used and
> divided by one thousand. Since the inefficiencies are these SMALL
> differences, any real electrical cost savings will be in pennies on the
> monthly bill and that is if the utili

[Repeater-Builder] minor formula typo in formula switching power supplies

[DaveH]

A minor formula exists in the P=EI formula in the original message. The 
corrected version is below. To many annoying phone calls! Sorry about that!
Dave
- Original Message - 
From: "DaveH" <[EMAIL PROTECTED]>
To: 
Sent: Sunday, January 14, 2007 6:27 PM
Subject: Re: [Repeater-Builder] Re: Switching Power Supply vs. Astron Etc.


> Erick,
>I agree with you!  The only difference will be any increased
> efficiencies in the switcher over the mag and that will be small. I have 
> had
> a Master Electrical License for 38 years. A physical law of science says
> that 746 watts equal 1 horsepower>  There is no deviation from that
> scientific fact.   In addition, if the equipment that is powered by the
> astron, draws 30 amps, it's going to draw 30 amps on the switcher. THAT
> CANNOT CHANGE>   The power supply, both switcher and mag type, will draw 
> the
> required line current that is demanded by  that load.  Ohm's law says P=EI
> (power ((wattage)) = E((voltage)) multiplied by the amperage ((I)).  If 30 
> amps
> are required at 13.8 volts  the resultant power consumed will REMAIN THE
> SAME POWERED BY THE MAG OR SWITCHER SUPPLY. Since this physical law cannot
> change, then the efficiency differences between the two types of supply 
> will
> be the ONLY POSSIBLE DECREASE IN CONSUMED ELECTRICITY.
>Since efficiency is the ONLY POSSIBLE GAIN and the switcher cannot
> generate electricity and there is no perpetual motion, needed magnetizing
> current decrease and possible utility current power factor improvements 
> are
> the ONLY POSSIBLE IMPROVEMENTS THAT CAN OCCUR. If you consider these 
> facts,
> you will instantly see that utility cost reductions will be minimal at 
> best.
> Electrical company power charges are calculated in KWH  (kilowatt hours).
> That is calculated by the formula  KHW (killer what  hours ((hi hi)) =
> wattage load (both apparent and actual) multiplied by the time used and
> divided by one thousand. Since the inefficiencies are  these SMALL
> differences, any real electrical cost savings will be in pennies on the
> monthly bill and that is if the utility apparent wattage is in line with
> actual use (power factor corrected).
>As you can see,  the only real advantage to the switching supplies are
> mostly physical. By the way. Accurately  measuring these electrical
> differences with  metering equipment can get quite complicated since ac
> power factor is involved.  To correctly  measure this you need to correct
> power factor by using correction capacitors. That is why utility meters 
> have
> a designed and approved accuracy of 1.5  to 2 percent (this is national
> standard and regulation required). If anyone believes they are going to 
> save
> any substantial amount of money by converting to switchers, they are going
> to be rudely awakened. It would take decades to recoup the cost of such
> equipment replacements based upon utility savings.
>One last myth left to clear up. A power supply connected to ac current
> and left turned on 24/7/365 is the way to insure increased equipment
> longevity. I have heard many people say they must "turn their power supply
> off when equipment is not being used to save electricity."  NOTHING COULD 
> BE
> MORE ERRONEOUS. The ONLY electricity being consumed when the load is
> switched off, is magnetizing current and voltage correction current from
> leakage etc.
> Since this is relatively minute, those "significant savings" are
> nonexistent. Once again we speak of pennies. If you consider the stress
> caused by switching the power supply on and off many times, in the end you
> loose. Life expectancy is decreased by in rush,  each time the unit is
> re-energized. I have had Astron mag. supplies functioning for DECADES with
> no failure. As long as the input is protected by GOOD electronic spike
> suppression,  failure is mostly limited to age or abuse (possible load
> shorts).
>I can only hope this helps clear up confusion and to eliminate
> conjecture regarding these subjects.
>
> David R. Henry  LME
>
> - Original Message - 
> From: "Eric Lemmon" <[EMAIL PROTECTED]>
> To: 
> Sent: Sunday, January 14, 2007 3:07 PM
> Subject: RE: [Repeater-Builder] Re: Switching Power Supply vs. Astron Etc.
>
>
>> Larry,
>>
>> You have a golden opportunity to provide an extremely valuable service to
>> the radio community!  If you can obtain the use of a wattmeter, you can
>> make
>> a comparison between the two power supplies.  One such meter is the "KILL
>> A
>> WATT" meter that is sold under several brand names.  It is inexpensive,
>> and
>> accurate enough for our purposes.
>>
>> Try measuring the power- both real and apparent- drawn by the same
>> equipment
>> while operating on the TPN1110B supply, and again while operating on the
>> TPN1151A supply.  Make a note of all parameters in both the idle state 
>> and
>> while transmitting.  I'll be surprised if the energy used by the switcher
>> is
>> not much less than the ferro-reso

[Repeater-Builder] SM8505

[Camilo So]

Can someone help me locate ma source for this Motorola I.C. SM8505 or 
20A99,can't find a cross ref.number for this,its a dual linear op-amp IC.
any help is highly appreciated thanks for your time.


73
W4CSO

[Repeater-Builder] WTB - Moto GM300's

[Tony L.]

Wanted - VHF & UHF GM300's

VHF- any split.

UHF- 438-470 split.

Any power level, any condition (working preferred).

16 pin connector mandatory.

Mics not needed, but mounting brackets & power cords would be nice.

Send private e-mail; include full model#, condition/accesories
available, and asking price.

Thanks.



Tony

Re: [Repeater-Builder] Radio Tone Control

[Kent Chong]

Dear Gareth,

We have 29 fixed sites with 6 VX-4200 radios preloaded with frequency. We have 
one control site with the PC to control the VX-4200, such as frequency 
changing, receive ANI, select call etc. The fixed sites and control site are 
far a part which could not be reach with RF signal. We are using VSAT to link 
the fixed sites and control site, IP based.

What is the VX-4200 controller that you are using? We are developping the 
controlling software in the control site PC. Would like to know the control 
protocol for the controller.

Best Regards,

Kent Chong  


- Original Message 
From: Gareth Bennett <[EMAIL PROTECTED]>
To: Repeater-Builder@yahoogroups.com
Sent: Thursday, 11 January 2007 6:36:06
Subject: Re: [Repeater-Builder] Radio Tone Control

Kent, 
It would be beneficial to know exactly what you wish to achieve, and to 
know more about your project/requirement s so that I can be of more assistance.
The VX-4200 is a very versatile radio and can preform numerous remote 
control functions.
 
Cheers
 _ _ _ _ _ 
 
Gareth Bennett
 
This e-mail is confidential, if you received this message in error, or you
are not the intended recipient,
please return it to the sender and destroy any copies.
Thank you.

- Original Message - 
From: Kent Chong 
To: Repeater-Builder@ yahoogroups. com 
Sent: Wednesday, January 10, 2007 11:45 PM
Subject: Re: [Repeater-Builder] Radio Tone Control


Dear Gareth,
 
We are using VX-4200 series and ICOM IC-F521 or F621 radio. Would like to know 
more how you do it. We know the VX-4200 has a DB15. How do we control the radio 
via the audio line?
 
Best Regards,
 
Chong Kwan Meng


- Original Message 
From: Gareth Bennett <[EMAIL PROTECTED] nz>
To: Repeater-Builder@ yahoogroups. com
Sent: Tuesday, 9 January 2007 6:14:39 PM
Subject: Re: [Repeater-Builder] Radio Tone Control


Vertex Standard VX-2200 and 4200 series radios can be channel changed via BCD 
addressible  pins from the rear sub DB15.
We utilise a UHF link radio (VX-2200 or 4200) to send 5 Tone commands that 
can be addressed via a configurable BCD output that can change the frequency 
and of course pass through the appropriate audio.
 
Let me know if this is the down the track that you are interested in, and I can 
supply you more info.
 _ _ _ _ _ 
 
Gareth Bennett
 
This e-mail is confidential, if you received this message in error, or you
are not the intended recipient,
please return it to the sender and destroy any copies.
Thank you.

- Original Message - 
From: Vincent Caruso 
To: Repeater-Builder@ yahoogroups. com 
Sent: Tuesday, January 09, 2007 6:47 PM
Subject: Re: [Repeater-Builder] Radio Tone Control


Some info can be found on the Midian site in pdf at the following link

http://www.midians. com/pdf/tone_ signaling. pdf

Telex has some info on their site as well, but most common commercial 
gear only interfaces to certain radios for multiple channel control 
otherwise you are limited to one two or four channel remotes.

Vince

Kent Chong wrote:
> Hello,
>  
> Would like to control ICOM, and Vertex radio remotelly by using the 
> tone, for example, change channel, PTT etc. Anybody know the remote 
> control tone standard? Where could I find the informtion?
>  
> Best Regards,
>  
> Chong Kwan Meng 
> 
> Send instant messages to your online friends 
> http://asia. messenger. yahoo.com 

 



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Re: [Repeater-Builder] AEA Isopole data needed at repeater-builder... file cabinet checking time...

[Nate Bargmann]

* [EMAIL PROTECTED] <[EMAIL PROTECTED]> [2007 Jan 14 21:54 -0600]:
> At 1/14/2007 17:01, you wrote:
> >* [EMAIL PROTECTED] <[EMAIL PROTECTED]> [2007 Jan 14 
> >11:33 -0600]:
> >
> > > I also have a 220 Isopole but no data sheet.  Never needed it,
> > > though.  AFAIK the upper decoupling cone mounts at the top of the mast 
> > near
> > > the feedpoint, & the 2nd cone mounts at the bottom of the 1st.  Then 
> > again,
> > > maybe I'm wrong & that's why that antenna never worked worth a darn.
> >
> >As I recall (been a long time) the upper cone had to be mounted below
> >the feedpoint a distance about equivalent to the length of the stinger.
> >The second cone did indeed mount below the first.
> 
> Yes, I see that from the prior posting of the instructions.  I guess that's 
> why it didn't work well for me.  I thought it was supposed to be a dipole 
> equivalent so figured the 1st cone goes right at the feedpoint.  Now I'd 
> like to know the theory behind the correct cone placement.

My recollection of its operation (greatly simplified) is that it was a
center-fed dual 5/8 wave collinear antenna.  The cones simply kept the
energy from continuing on down the mast and onto the coax shield.  The
result was a very low angle of radiation and a narrow vertical
beamwidth.  Trust me, an Isopole does not work well for picking up a
satellite more than a few degrees above the horizon.  ;-)

73, de Nate >>

-- 
 Wireless | Amateur Radio Station N0NB  |  Successfully Microsoft
  Amateur radio exams; ham radio; Linux info @  | free since January 1998.
 http://www.qsl.net/n0nb/   |  "Debian, the choice of
 My Kawasaki KZ-650 SR @| a GNU generation!"
http://www.networksplus.net/n0nb/   |   http://www.debian.org

Re: [Repeater-Builder] AEA Isopole data needed at repeater-builder... filecabinet checking time...

[Chuck Kelsey]

Stacked sleeve (coaxial) antennas have been around for a long time, probably 
since the 40's or 50's.

Like these:

http://www.krecoantennas.com/stackedcaxial.htm

Chuck
WB2EDV



- Original Message - 
From: <[EMAIL PROTECTED]>
To: 
Sent: Monday, January 15, 2007 12:42 AM
Subject: Re: [Repeater-Builder] AEA Isopole data needed at 
repeater-builder... filecabinet checking time...


> Back in the '70s we built an antenna for the VHF repeater in Commerce,
> TX that used the same type design as the Isopole, although I have never
> examined an Isopole in detail. (I think it came along much later)  We
> ran across the design somewhere and it used a combination of 3/4 and 1
> inch steel electrical conduit. The antenna was very simple, with a 1/4
> wave stinger sticking out the top and connected to the center of the
> coax. A 1/4 wave section of 1 inch conduit was welded to a washer that
> had been cut out to clear the top and was welded to the top of the 3/4
> inch conduit main mast, and was air insulated from the weld at the top
> down to the open skirt at the bottom. The shield of the coax was
> connected to the top of this first 1/4 wave section. Then 1/4 wave
> below the first skirt, another 1/4 wave section of 1 inch conduit was
> welded to the mast at the top and open at the bottom, using another
> washer cut out to clear the mast. Another 1/4 wave below that was
> another 1/4 wave section of one inch tubing welded to the mast at the
> top.
>
> The article as I recall mentioned that the lower sections of the
> antenna were 'shock' excited by the top section, and contributed in
> phase to the overall radiation of the antenna. We had excellent
> operation with this antenna until the first lightning strike which took
> out the coax all the way back to the duplexer.
>
> Absolutely no ground provided by the antenna to the center conductor
> with this lash up. Excellent SWR and bandwidth from this simple antenna
> until the demise of the coax. It was located on top of a light standard
> at the football field.
>
> Electrically the antenna was three half waves in phase, but the three
> sections were not fed equal power.
>
> 73 - Jim W5ZIT
>
> 

Re: [Repeater-Builder] E-prom Reader-Writer for Phoenix

[Richard W BAZELL JR]

Hi Jim,

Would be interested in taking you up on that offer. have 2 GE Phoenix(16
Channel) one VHF, one UHF,which would like the Chips programmed. was
looking for your e-mail address on ARRL website, where I could reply
direct to you, instead of tying up the Repeater-Builder Website. My
e-mail address is [EMAIL PROTECTED]

Wesley AB8KD