http://nepp.nasa.gov/whisker/

I've fixed two cell phones for friends and I have a very nice MP3
player I got for $1.

Each was fixed with a stiff brush with a combination of compressed air
(outside) and
a vac inside.

-pete

PS if you do the air thing don't forget about static use a ionizer.

On Wed, Feb 16, 2011 at 1:58 PM, Bob Camp lists@rtty.us wrote:

Interestingly it was not your normal tin whisker (I have seen a few of
those, just..) it was a substantial one that had grown out from the
stack of 2 Ceramic caps in series with the coil to the RF choke in
series with the DC supply to the lamp housing.

It might even have been a solder blob left over from production but it
looked quite crystalline.
It's a bit ugly in the lamp assy because the heat and strong RF field
made a bit of a mess of insulation on the RFC and the heater leads but
everything else seems ok

I'll try and locate an MRF134 and see how I get on, certainly worth the
price and time by the sounds of it.

thanks for all the help and encouragement

On 16/02/2011 22:14, Pete Lancashire wrote:

--
73
Brendan EI6IZ

It sucks, but they may only have a small qty of the spares, and they keep them for those customers who paid full price.

However, I agree about the high price. That would be better than "go away"

Didier KO4BB

Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: lists@lazygranch.com
Sender: time-nuts-bounces@febo.com
Date: Wed, 16 Feb 2011 20:37:38
To: Discussion of precise time and frequency measurementtime-nuts@febo.com
Reply-To: lists@lazygranch.com,
Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] SRS PRS10 problem

If you want to write a turd note about their service, I will pin it on their door. These companies need to know the reach of the internet.

If they had any brains, they would offer you a replacement at a ridiculously high price.

-----Original Message-----
From: Brendan Minish ei6iz.brendan@gmail.com
Sender: time-nuts-bounces@febo.com
Date: Wed, 16 Feb 2011 20:11:37
To: time-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] SRS PRS10 problem

Right, to follow up on my own email

I took it apart
The lamp assembly has failed.

In the PRS10 the lamp is exited by a strong RF field @ 150Mhz
this is generated by an MRF134 within the lamp package

The failure mode was caused by the growth of a substantial tin whisker
within the lamp assembly which appears to have killed the MRF134.

I made contact with SRS about purchasing a replacement lamp assembly but
since I bought it on the used market they are not willing sell me a
replacement lamp assembly. Frankly I am not terribly impressed with
their response on this.

Does anyone on list have a 'donor' PRS10 that might have a good lamp
assembly that they would be willing to sell me ?
Perhaps someone on list has a commercial relationship with SRS and might
be able to assist me with purchasing it?

Hoping someone can help out, My alternative is to attempt to source an
MRF134 and have a go at replacing it but there may be other damage in
there

regards
Brendan

On 14/02/2011 18:53, Brendan Minish wrote:

--
73
Brendan EI6IZ

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

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and follow the instructions there.

On 02/17/2011 12:23 PM, shalimr9@gmail.com wrote:

Full price?

Someone payed full price for it originally. The notion that can have
control over who owns it later is strange and not relevant. Sending it
to them for repairs may be possible thought.

Cheers,
Magnus

I wanted to say "those customers who bought them new directly from them"

While I do not agree with the practice, many companies treat their primary customers better than those who buy aftermarket.

What is relevant is what the vendor believes is relevant. What you and I think about it IS irrelevant.

They do not want to exert control on who owns it later, but they exert control on what they do with their spares.

Its a fact of life.

Didier KO4BB

Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: Magnus Danielson magnus@rubidium.dyndns.org
Sender: time-nuts-bounces@febo.com
Date: Thu, 17 Feb 2011 18:26:41
To: time-nuts@febo.com
Reply-To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] SRS PRS10 problem

On 02/17/2011 12:23 PM, shalimr9@gmail.com wrote:

Full price?

Someone payed full price for it originally. The notion that can have
control over who owns it later is strange and not relevant. Sending it
to them for repairs may be possible thought.

Cheers,
Magnus

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Just a follow-up for others that may run into this someday

I took apart the PRS10 and disassembled the lamp assembly, Not easy..

I discovered that the MRF134 in there was still functional but that
there was a second short that was preventing oscillation, this looked to
be due to solder reflowing slightly from a joint to a chip cap had been
soldered with an excess amount of solder in manufacturing

I removed this, tested the fet which was still ok but would be a real
bear to replace. I then tested each discreet component (ceramic caps
with LC meter, resistors etc)
I put the lamp assy and the PRS 10 back together

Now looking though the hole provided I can see that after a short warmup
the lmap now does light (it didn't previously)  however the unit no
longer locks to Rb

I have shelved the PRS10 and rebuilt my reference around a Trimble
thunderbolt.
Perhaps at a later date I'll have another go at it
thanks for all the help

On Wed, 2011-02-16 at 22:37 +0000, Brendan Minish wrote:

--
73
Brendan EI6IZ