to replace my power supplies in the future. Bruce
KD4BOH.-
Original Message -
From: Joe Montierth [EMAIL PROTECTED]
To: Repeater-Builder@yahoogroups.com
Sent: Wednesday, May 25, 2005 2:22 PM
Subject: Re: [Repeater-Builder] IOTA Switched Power Supply and
Noise?
I have one of the 75 amp supplies
At 09:43 AM 7/19/2005, Gran Clark wrote:
Joe
Carefully consider expanding into switchers. The designs are quite
varied. To repair them you really need a good high frequency scope,
shielded isolation transformer, 0.18 ohm 1000 watt resistor load,
and most of all a good schematic. Switcher
Dave's points are good, I'd like to point out a couple
of other things.
We have used Astron supplies for years, and overall
have been happy with them. There are some drawbacks,
mainly the analog design is very wasteful of power,
and the units get very warm (hot). I have done some
measurements,
If you do the calculations on wasted heat, this comes
to an additional 4147 KWh per year on the Astron, and
an additional 1175 KWh/ year on the IOTA. If you live
in an area with 10 cents/KHh power (typical) then your
power savings in one year will be almost $300.
We don't pay the power bill at
Anyone have an idea how much power would be saved by running a MSF-5000
that is idle most of the time from a switcher instead of the stock heavy
iron power supply?. The transformers produce a lot of heat just in
standby mode. I have several of these machines on line and also a GE
repeater
The easiest way to tell would be to measure the AC
current draw in idle. Then measure the DC current draw
in idle.
You can get a pretty close watt figure by multiplying
the amps times the voltage (115v) on the input side,
and doing the same thing on the DC side. The
difference between the two is
One nit-pick: measure the actual AC line voltage and use it
where Joe has 115v. Locally it's 118-123v, depending on
the local load (i.e. lower on a summer day, highest during
a winter night).
And sometime when you have a free hour, wander around
the house and count how many wall warts you have
Think how many houses have that exact same situation.
I know I suffer from this big-time.
Lots of wall wart devices.
They are going to switchers though, it's finally come to the place
where the switcher is cheaper than the iron and shipping from China.
Last year, I needed a new wart for
--- Mike Morris WA6ILQ [EMAIL PROTECTED] wrote:
I did this at a friend house and we ended up with
about 20
plugged into a half-dozen power strips and totalling
about
2 and a half amps of AC... He's got 112-114v of AC
at his
house so using 113 we get 255.2w ... divide by 1000
and
times
At 05:18 PM 7/19/2005, Tony King, W4ZT wrote:
One caution about these switchers. Many of the cheap switchers being
made today both as chargers and supplies generate tremendous amounts of
RFI. A number of my ham friends have experienced unbearable
interference from these devices. Note that they
] IOTA Switched Power Supply and Noise?
Think how many houses have that exact same situation.
I know I suffer from this big-time.
Lots of wall wart devices.
They are going to switchers though, it's finally come to the place
where the switcher is cheaper than the iron and shipping from China
: [Repeater-Builder] IOTA Switched Power Supply and Noise?
I have one of the 75 amp supplies working at a remote
site. We have not seen any noise from the unit, but
our equipment is all VHF and UHF, haven't checked it
down in HF, but at UHF we have seen no problems. We
have 20 UHF RX's and 6 VHF
At 06:49 PM 7/17/2005, Bruce Nanney wrote:
Does anybody have a web site to look at IOTA power supply? I need to find
some to replace my power supplies in the future. Bruce KD4BOH.-
I picked up one on ebay recently, very competitive pricing.
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To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
Does anybody have a web site to look at IOTA power supply? I need to find
some to replace my power supplies in the future. Bruce KD4BOH.-
Original Message -
From: Joe Montierth
I have one of the 75 amp supplies working at a remote
site. We have not seen any noise from the unit, but
our equipment is all VHF and UHF, haven't checked it
down in HF, but at UHF we have seen no problems. We
have 20 UHF RX's and 6 VHF and have not seen any
degradation.
These IOTA's run much
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