MailLists | 17 Mar 10:59 2012
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Temex LPFRS-01

Hello all,

a friend purchased from the bay a <subj.> in the LPRO configuration. 
After some problems encountered during the first power ups, he asked for 
help - I'm passing the questions further...
After about 9 minutes of warm-up from room temperature (22°C) the lock 
signal goes low, but after a short time starts to switch low/high with 
decreasing low periods, until it remains high with short low pulses, 
spaced at about 2 seconds. After power-down, and sufficient cooling 
time, the cycle repeats.
First step was to reapply the thermal interface to the integrated Al 
radiator, which helped a bit, the time during which the unit is locked 
growing slightly.
Next step was forced cooling, which helped more, so the lock loss could 
be attributed with high probability to elevated operating temperatures. 
The temperature of the base plate (integrated Al radiator) at which lock 
gets lost is about 40°C, so for a reasonable operation it should not 
pass about 36°C, at which the power consumption raises to about 17W. 
That also means that for a 1°C/W heat sinking - obtainable with a larger 
passive HS or active cooling - operation above 30°C ambient gets 
practically impossible (except refrigeration, Peltier, etc.).

Any further help or suggestions are welcome.

Regards,
bbg

Azelio Boriani | 17 Mar 15:10 2012
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Re: Temex LPFRS-01

LPFRS from fluke.l? OK, then open it up and clean it, the LPFRS from
fluke.l suffers from high humidity/water immersion and usually are very
rusty inside. I have received one that was very bad but after cleaning with
tetrachloroethylene (translated with google) it is working properly, maybe
it will fail soon but now works. I complained with fluke.l and he refunded
me without asking to ship back the LPFRS.
TIP: handle with extreme care an opened LPFRS, there is a flexible PCB that
holds the DB9 connector that can tear in the corners.

On Sat, Mar 17, 2012 at 10:59 AM, MailLists <lists@...> wrote:

> Hello all,
>
> a friend purchased from the bay a <subj.> in the LPRO configuration. After
> some problems encountered during the first power ups, he asked for help -
> I'm passing the questions further...
> After about 9 minutes of warm-up from room temperature (22°C) the lock
> signal goes low, but after a short time starts to switch low/high with
> decreasing low periods, until it remains high with short low pulses, spaced
> at about 2 seconds. After power-down, and sufficient cooling time, the
> cycle repeats.
> First step was to reapply the thermal interface to the integrated Al
> radiator, which helped a bit, the time during which the unit is locked
> growing slightly.
> Next step was forced cooling, which helped more, so the lock loss could be
> attributed with high probability to elevated operating temperatures. The
> temperature of the base plate (integrated Al radiator) at which lock gets
> lost is about 40°C, so for a reasonable operation it should not pass about
> 36°C, at which the power consumption raises to about 17W. That also means
> that for a 1°C/W heat sinking - obtainable with a larger passive HS or
(Continue reading)

Bob Camp | 17 Mar 15:21 2012
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Re: Temex LPFRS-01

Hi

If it is water immersion damage, wash it in soap and water. Then rinse it in hot deionized water (above 10 mega
ohms if you can get it). After that bake it at 80C with good air flow for > 24 hours. It still may rust, but most
of the guck from the water will be gone.

I once spent a lot of quality time with many truck loads of flood damaged gear....

Bob

On Mar 17, 2012, at 10:10 AM, Azelio Boriani <azelio.boriani <at> screen.it> wrote:

> LPFRS from fluke.l? OK, then open it up and clean it, the LPFRS from
> fluke.l suffers from high humidity/water immersion and usually are very
> rusty inside. I have received one that was very bad but after cleaning with
> tetrachloroethylene (translated with google) it is working properly, maybe
> it will fail soon but now works. I complained with fluke.l and he refunded
> me without asking to ship back the LPFRS.
> TIP: handle with extreme care an opened LPFRS, there is a flexible PCB that
> holds the DB9 connector that can tear in the corners.
> 
> On Sat, Mar 17, 2012 at 10:59 AM, MailLists <lists <at> medesign.ro> wrote:
> 
>> Hello all,
>> 
>> a friend purchased from the bay a <subj.> in the LPRO configuration. After
>> some problems encountered during the first power ups, he asked for help -
>> I'm passing the questions further...
>> After about 9 minutes of warm-up from room temperature (22°C) the lock
>> signal goes low, but after a short time starts to switch low/high with
(Continue reading)

Azelio Boriani | 17 Mar 15:58 2012
Picon

Re: Temex LPFRS-01

Yes, correct. The problem is that I have no deionized water nor a suitable
oven. The use of the tetrachloroethylene has simplified the procedure for
me (after all I was refunded, should the Rb fail it is not a money loss).
Anyway I'll try to locate a supply for high quality deionized water, the
oven can be built... I have one item to process more carefully.

On Sat, Mar 17, 2012 at 3:21 PM, Bob Camp <lists@...> wrote:

> Hi
>
> If it is water immersion damage, wash it in soap and water. Then rinse it
> in hot deionized water (above 10 mega ohms if you can get it). After that
> bake it at 80C with good air flow for > 24 hours. It still may rust, but
> most of the guck from the water will be gone.
>
> I once spent a lot of quality time with many truck loads of flood damaged
> gear....
>
> Bob
>
>
>
> On Mar 17, 2012, at 10:10 AM, Azelio Boriani <azelio.boriani@...>
> wrote:
>
> > LPFRS from fluke.l? OK, then open it up and clean it, the LPFRS from
> > fluke.l suffers from high humidity/water immersion and usually are very
> > rusty inside. I have received one that was very bad but after cleaning
> with
> > tetrachloroethylene (translated with google) it is working properly,
(Continue reading)

ehydra | 17 Mar 16:18 2012
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Re: Temex LPFRS-01

You must understand the difference between deionized and destillated 
water! I think often they sell deionized water of poor quality as 
destillated on gas stations etc. Much like "destillated" as a general 
synonym for "the best water".

If all fails, simple rain water is very good. Wait for a heavy rain and 
throw the first litres because of salts and other ingredients coming 
from your roof. Then get the water you want. Discretes can be removed by 
a coffee filtre.

Or buy it at a chemicals supplier.

Testing can be done with a resistance meter if you carefully control the 
mechanical parameters of your two metalic plates.

I wonder that you can still buy TCE. I thought it is banned in EU. I 
know that is a wonderful cleaning product.

- Henry

Azelio Boriani schrieb:
> Yes, correct. The problem is that I have no deionized water nor a suitable
> oven. The use of the tetrachloroethylene has simplified the procedure for
> me (after all I was refunded, should the Rb fail it is not a money loss).
> Anyway I'll try to locate a supply for high quality deionized water, the
> oven can be built... I have one item to process more carefully.

--

-- 
ehydra.dyndns.info

(Continue reading)

MailLists | 18 Mar 09:26 2012
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Re: Temex LPFRS-01

Yes...
Thank you, and the others, for the suggestions for cleaning/reviving the 
unit, but I can't recommend to my friend to keep a pile of rust (if 
water damage really is the problem) advertised as an used working item.

Regards,
bbg

On 3/17/2012 4:10 PM, Azelio Boriani wrote:
> LPFRS from fluke.l? OK, then open it up and clean it, the LPFRS from
> fluke.l suffers from high humidity/water immersion and usually are very
> rusty inside. I have received one that was very bad but after cleaning with
> tetrachloroethylene (translated with google) it is working properly, maybe
> it will fail soon but now works. I complained with fluke.l and he refunded
> me without asking to ship back the LPFRS.
> TIP: handle with extreme care an opened LPFRS, there is a flexible PCB that
> holds the DB9 connector that can tear in the corners.
>
> On Sat, Mar 17, 2012 at 10:59 AM, MailLists<lists@...>  wrote:
>
>> Hello all,
>>
>> a friend purchased from the bay a<subj.>  in the LPRO configuration. After
>> some problems encountered during the first power ups, he asked for help -
>> I'm passing the questions further...
>> After about 9 minutes of warm-up from room temperature (22°C) the lock
>> signal goes low, but after a short time starts to switch low/high with
>> decreasing low periods, until it remains high with short low pulses, spaced
>> at about 2 seconds. After power-down, and sufficient cooling time, the
>> cycle repeats.
(Continue reading)

MailLists | 12 Apr 17:00 2012
Picon

Re: Temex LPFRS-01

Well, the saga continues...
A replacement part (for which a thorough check was specifically asked) 
has arrived. It boasts a "Checked OK" written with a marker pen on the 
label. Promising...
With high expectations, the necessary connections were made, power 
applied, and after warming up it locks at precisely 9.999,817,1 MHz... 
bummer.
Sometimes, for (yet) unknown reasons, it unlocks again, and, if the 
frequency adjustment trend is upwards, it locks again at ~10.000.000 
MHz. The lock signal is active even at higher temperatures - that's 
quite better than the first unit, but after a power cycle the story 
repeats... mostly the wrong frequency comes out, but, on the brighter 
side, it's locked.

On 3/18/2012 10:26 AM, MailLists wrote:
> Yes...
> Thank you, and the others, for the suggestions for cleaning/reviving the
> unit, but I can't recommend to my friend to keep a pile of rust (if
> water damage really is the problem) advertised as an used working item.
>
> Regards,
> bbg
>
>
> On 3/17/2012 4:10 PM, Azelio Boriani wrote:
>> LPFRS from fluke.l? OK, then open it up and clean it, the LPFRS from
>> fluke.l suffers from high humidity/water immersion and usually are very
>> rusty inside. I have received one that was very bad but after cleaning
>> with
>> tetrachloroethylene (translated with google) it is working properly,
(Continue reading)

Azelio Boriani | 12 Apr 18:50 2012
Picon

Re: Temex LPFRS-01

Interesting... have to check my LPFRS now: only tested for the lock
indicator when received and then put aside to complete first the
"discipliner".

On Thu, Apr 12, 2012 at 5:00 PM, MailLists <lists@...> wrote:

> Well, the saga continues...
> A replacement part (for which a thorough check was specifically asked) has
> arrived. It boasts a "Checked OK" written with a marker pen on the label.
> Promising...
> With high expectations, the necessary connections were made, power
> applied, and after warming up it locks at precisely 9.999,817,1 MHz...
> bummer.
> Sometimes, for (yet) unknown reasons, it unlocks again, and, if the
> frequency adjustment trend is upwards, it locks again at ~10.000.000 MHz.
> The lock signal is active even at higher temperatures - that's quite better
> than the first unit, but after a power cycle the story repeats... mostly
> the wrong frequency comes out, but, on the brighter side, it's locked.
>
>
> On 3/18/2012 10:26 AM, MailLists wrote:
>
>> Yes...
>> Thank you, and the others, for the suggestions for cleaning/reviving the
>> unit, but I can't recommend to my friend to keep a pile of rust (if
>> water damage really is the problem) advertised as an used working item.
>>
>> Regards,
>> bbg
>>
(Continue reading)

MailLists | 18 Apr 10:29 2012
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Re: Temex LPFRS-01

That would be the tougher part, as, with highest probability, the 
external analog adjustment is first AD converted in the MPU (AIN4) 
summed with the internally stored fine adjustment value, and then 
applied to the C-Field correction, through an external DAC8800.
As both conversions are 8 bit, the obtained resolution of 1E-11 is 
insufficient to discipline the unit with enough accuracy, it was just 
meant to adjust the working frequency.

In the last day of the easter holidays I opened one up, and now I'm 
trying to grasp the inner workings... time allowing.

On 4/12/2012 7:50 PM, Azelio Boriani wrote:
> Interesting... have to check my LPFRS now: only tested for the lock
> indicator when received and then put aside to complete first the
> "discipliner".
>
> On Thu, Apr 12, 2012 at 5:00 PM, MailLists<lists@...>  wrote:
>
>> Well, the saga continues...
>> A replacement part (for which a thorough check was specifically asked) has
>> arrived. It boasts a "Checked OK" written with a marker pen on the label.
>> Promising...
>> With high expectations, the necessary connections were made, power
>> applied, and after warming up it locks at precisely 9.999,817,1 MHz...
>> bummer.
>> Sometimes, for (yet) unknown reasons, it unlocks again, and, if the
>> frequency adjustment trend is upwards, it locks again at ~10.000.000 MHz.
>> The lock signal is active even at higher temperatures - that's quite better
>> than the first unit, but after a power cycle the story repeats... mostly
>> the wrong frequency comes out, but, on the brighter side, it's locked.
(Continue reading)

Azelio Boriani | 18 Apr 12:25 2012
Picon

Re: Temex LPFRS-01

I'm not using the analog input but the serial port, yes, this doesn't
improve the 1E-11 step but at least I skip the first A/D conversion. The
direct access to the C-field control seems necessary but I like to have my
stuff in the original state. My LPFRS is very rusty so I can drop my "keep
it original" rule.

On Wed, Apr 18, 2012 at 10:29 AM, MailLists <lists@...> wrote:

> That would be the tougher part, as, with highest probability, the external
> analog adjustment is first AD converted in the MPU (AIN4) summed with the
> internally stored fine adjustment value, and then applied to the C-Field
> correction, through an external DAC8800.
> As both conversions are 8 bit, the obtained resolution of 1E-11 is
> insufficient to discipline the unit with enough accuracy, it was just meant
> to adjust the working frequency.
>
> In the last day of the easter holidays I opened one up, and now I'm trying
> to grasp the inner workings... time allowing.
>
>
> On 4/12/2012 7:50 PM, Azelio Boriani wrote:
>
>> Interesting... have to check my LPFRS now: only tested for the lock
>> indicator when received and then put aside to complete first the
>> "discipliner".
>>
>> On Thu, Apr 12, 2012 at 5:00 PM, MailLists<lists@...>  wrote:
>>
>>  Well, the saga continues...
>>> A replacement part (for which a thorough check was specifically asked)
(Continue reading)

MailLists | 18 Apr 15:30 2012
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Re: Temex LPFRS-01

The disadvantage of the digital adjustment is that it's meant to be 
"permanent", the MPU also modifies it's internal EEPROM cell that stores 
the new value. Too many adjustments bear the risk of the used EEPROM 
cell wearing out, which would be inevitable in a disciplining process, 
and an unknown reaction of the firmware to such an event.
Initially, I thought too it would be more convenient to use the serial 
interface for disciplining (this being one of the criteria favoring the 
LPFRS) but after a detailed reading of the specs it's clearly unusable 
as such.
A dual pronged approach, with the external analog input rerouted to the 
C-Field adjustment circuit (with a narrower control range, equivalent to 
that of a few digital steps), and the digital "fine" adjustment used 
just when the analog range exhausts, should be the right one.

Did your lock output test succeed?

On 4/18/2012 1:25 PM, Azelio Boriani wrote:
> I'm not using the analog input but the serial port, yes, this doesn't
> improve the 1E-11 step but at least I skip the first A/D conversion. The
> direct access to the C-field control seems necessary but I like to have my
> stuff in the original state. My LPFRS is very rusty so I can drop my "keep
> it original" rule.
>
> On Wed, Apr 18, 2012 at 10:29 AM, MailLists<lists@...>  wrote:
>
>> That would be the tougher part, as, with highest probability, the external
>> analog adjustment is first AD converted in the MPU (AIN4) summed with the
>> internally stored fine adjustment value, and then applied to the C-Field
>> correction, through an external DAC8800.
>> As both conversions are 8 bit, the obtained resolution of 1E-11 is
(Continue reading)

Mark Spencer | 17 Mar 17:20 2012
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Re: Temex LPFRS-01


This is interesting.  I have two temex units one which works and one which has similar issues to yours.  The
performance of my working one is quite good.   (If you want any specifics let me know and I can provide more
details in a few days, but I recall it is notably better than either of  my 5680's.  I found the performance was
best with a fan blowing air over the heat sink.)

I'm glad you were able to get a refund for yours.  I gave up debating with the seller of my defective unit and
wrote it off to experience (also I figured since it did put out a signal and locked up from time to time that it 
wasn't entirely dead.) I probably should have pushed harder with the seller.

I'll leave my busted temex in the projects pile for now.

With the benefit of hindsight the picture I saw on ebay of the non working unit was not very confidence
inspiring and I wish I had bought a second unit from the original source.

The first unit was very clean and came with an attached heat sink and worked fine from day one.  

I've been contemplating building a system to periodically adjust the frequency and I want a second working
unit before I put any time and effort into sorting out a pic tic micro controller solution.

Please excuse typos and top  posting sending from pda.
------------------------------
On Sat, 17 Mar, 2012 10:58 AM EDT Azelio Boriani wrote:

>Yes, correct. The problem is that I have no deionized water nor a suitable
>oven. The use of the tetrachloroethylene has simplified the procedure for
>me (after all I was refunded, should the Rb fail it is not a money loss).
>Anyway I'll try to locate a supply for high quality deionized water, the
>oven can be built... I have one item to process more carefully.
>
(Continue reading)

Azelio Boriani | 17 Mar 17:58 2012
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Re: Temex LPFRS-01

Yes, trichloroethylene is banned but not tetrachloroethylene that was used
when the first was banned.
Fluke.l has other LPFRS but beware: they are much worst than the one in the
picture, usually they go on auction so try to stay low should you ever want
to bid on one.
Actually item 29068516928 is on auction at $1.75 due on the 27th.

On Sat, Mar 17, 2012 at 5:20 PM, Mark Spencer <mspencer12345@...>wrote:

>
> This is interesting.  I have two temex units one which works and one which
> has similar issues to yours.  The performance of my working one is quite
> good.   (If you want any specifics let me know and I can provide more
> details in a few days, but I recall it is notably better than either of  my
> 5680's.  I found the performance was best with a fan blowing air over the
> heat sink.)
>
> I'm glad you were able to get a refund for yours.  I gave up debating with
> the seller of my defective unit and wrote it off to experience (also I
> figured since it did put out a signal and locked up from time to time that
> it  wasn't entirely dead.) I probably should have pushed harder with the
> seller.
>
> I'll leave my busted temex in the projects pile for now.
>
> With the benefit of hindsight the picture I saw on ebay of the non working
> unit was not very confidence inspiring and I wish I had bought a second
> unit from the original source.
>
> The first unit was very clean and came with an attached heat sink and
(Continue reading)

MailLists | 18 Mar 09:50 2012
Picon

Re: Temex LPFRS-01

After further testing, including a simple lost lock detector (2 555s: 
manually resettable bistable + multivibrator and a buzzer), with the 
serial port the whole picture looks even grimmer. Most parameters seem 
to be in nominal range, relatively stable after warmup, with the notable 
exception of a very low dip detector amplitude, which fluctuates, and 
also gets lower with increasing temperature. Even at lower temperatures, 
than first mentioned, lock losses do appear sporadically.

Regarding the adjusting of the LPFRS's frequency, it seems it's possible 
just discreetly, even with the analog input, the smallest step being 
1E-11, as the analog way is, with high probability, also going through 
an 8 bit ADC and the CPU. To have a more fine control, the access 
directly to the internal C-Field adjustment circuit seems necessary - 
maybe a future project with a fully working unit.

Regards,
bbg

PS: Mark, is the busted one from the same source, mentioned earlier?

On 3/17/2012 6:20 PM, Mark Spencer wrote:
>
> This is interesting.  I have two temex units one which works and one which has similar issues to yours.  The
performance of my working one is quite good.   (If you want any specifics let me know and I can provide more
details in a few days, but I recall it is notably better than either of  my 5680's.  I found the performance was
best with a fan blowing air over the heat sink.)
>
> I'm glad you were able to get a refund for yours.  I gave up debating with the seller of my defective unit and
wrote it off to experience (also I figured since it did put out a signal and locked up from time to time that it 
wasn't entirely dead.) I probably should have pushed harder with the seller.
(Continue reading)


Gmane