[1000mp] 1000MP Power Supplies

Thu Sep 7 22:16:59 EDT 2006

no i'm hot hal, but i do have a weco model 302, hi.  thanks for the 
information--makes sense that those big step down irons would smooth 
out the spikes somewhat.  Glad my house is on a surge protector at the 
entrance panel.  maybe my mk v switching supply will last a bit longer. 
  I believe Astron makes a 28 v. supply--if I ever have to replace the 
yaesu unit i'll look into running the rig off of two astrons.  Can't 
remember if the 28 v. astron is linear or not.

73,

rob / k5uj

On Thursday, September 7, 2006, at 10:08 AM, Harold Mandel wrote:

> Dear Rob,
>
> The main root cause of failure in switching PDU's are power line 
> transients.
>
> Where buck'n'boost isolation xfmrs are used, like in broadband 
> microwave
> (toll) floors, the incidence is less because the windings filter out 
> and
> decrease
> the voltage of the spikes, and as you know, RF has a hard time going 
> through
> xfmr
> windings.
>
> In cell sites it is absolutely horrendous because there's no isolation 
> and
> very little
> filtering. Some sites have these three-phase MOV units, and that helps 
> some,
> but when your
> equipment is running 24/7 on the plant it senses spikes 24/7.
>
> We use Marconi (Lorain), Delta, C&D, Tyco, Ericsson and Purcell PDU's. 
> The
> Chinese
> built stuff is the worst. I think these people are crazy, putting the
> telephone plant on
> Chinese rectifiers. What happens when they say "No more parts, G.I.,"?
>
> I see older 1231H plants that have been cranking -48 volts for over 20
> years,
> and most of them don't even need capacitors more than every 10 years.
>
> Are you a Bell hand?
>
>
>
>
>   Hal Mandel
>
>
> -----Original Message-----
> From: 1000mp-bounces at mailman.qth.net 
> [mailto:1000mp-bounces at mailman.qth.net]
> On Behalf Of Rob Atkinson
> Sent: Tuesday, September 05, 2006 9:08 PM
> To: All about Yaesu 1000mp
> Subject: Re: [1000mp] 1000MP Power Supplies
>
> hal,
>
> are you aware of any consistencies in failure mode for the switching
> supplies?  be interesting and maybe useful for troubleshooting to know
> if there are one or two particular components that die, for a general
> switching supply design.
>
> tnx
>
> rob / k5uj
>
> On Tuesday, September 5, 2006, at 09:37 AM, Harold Mandel wrote:
>
>> After reading somewhere about possible switching
>> noise (hash) generated by the FP-29 power supply
>> it was decided to look further into the situation.
>>
>> Firstly, dealing with switching supplies in my
>> workplace it is found that switching supplies
>> have a much lower MTBF than linear supplies, and
>> that we replace three times more switchers than
>> linears in the telephone central office.
>>
>> Secondly, the issue of hash and bypassing of the FP-29
>> caused me to listen to the radio and FP-29 running
>> with another HF radio not connected to the system,
>> but running on a battery. With no other appliances
>> running there were some "birdies" in the 3 MHz
>> band that were apparent and some stuff around
>> 18MHz that were audible as well.
>>
>> So I decided to invest in a couple of Astron linear
>> supplies, an RS-70M and an LS-25A.
>>
>> Before ever connecting these some e-mails were
>> read where Astrons catch fire on the circuit board
>> attaching to the one computer-grade filter cap used
>> in the supplies. Both the LS and RS use only one
>> capacitor, but these are different voltage ratings.
>>
>> The LS supply does not come with a fan. The RS
>> does, and it works when a thermostat mounted on
>> the right side heatsink closes. This is easily bypassed
>> with a front panel switch. Both supplies grow warm
>> when touching the top steel covers after an hour of
>> operation.
>>
>> A fan from Radio Shack was added to the LS supply
>> with an afternoon's work on the kitchen table. The fan
>> attaches to the rear apron, mounted outside, and there
>> is ample room to do so. The power is derived from
>> the front panel power switch, with no thermostat.
>>
>> The LS is able to be adjusted beyond 30.00 volts.
>> By attaching a 250 watt, 6 ohm resistor across the
>> output the voltage sag observed is less than 1/2 volt
>> under load from no load. The output was set at 30.00
>> volts for the '1000MP.
>>
>> Replacement capacitors are on the way for both these units. The
>> LS uses a 55 volt, 35,000uF cap. This will be replaced with
>> two units of 35,000uF at 80 WVDC. Four of these caps
>> were purchased, and the other two will replace the
>> 35,000uF/50 volt cap in the RS unit.
>>
>> A Molex-type plug and/or socket was desired for hooking
>> up the radio to the supply, with a jumpered arrangement
>> from the other supply. No part could be found from Yaesu
>> parts department. That Molex connector is not available
>> at all. Another power cord was ordered so as not to destroy
>> the OEM power cord for the FP-29. This was stripped and
>> converted into ring terminal ends to fit the Astrons.
>>
>> When completed and turned up & tested, the same jig was
>> used with another radio listening.
>>
>> Regrettably, the same "birdies" were heard. I cannot report to you
>> any reduction in noise by going through this exercise.
>>
>> The noises heard on the '1000MP stayed the same. However, here
>> in the "portable" location the RF environment is replete with all 
>> sorts
>> of signals as this is near many other appliances such as computers and
>> television sets, etc. It would take days to write down all the 
>> spurious
>> noises heard on the HF bands. However, the "biggies" were all still
>> there.
>>
>> Respectfully,
>>
>>   Hal Mandel, W4HBM
>>
>>
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