On 5/3/2018 9:55 AM, Bob kb8tq wrote:
Hi
You *really* need to keep the baseplate of the FRK series devices down. Their
reliability drops quite a bit
as you go from 40 to 50 to 60 C on the baseplate. I would avoid boosting the
input voltage without a very
good heatsink ( or heatsink + fan ) set
: time-nuts@febo.com
Subject: Re: [time-nuts] Racal 9475 Rubidium
On 5/3/2018 7:38 AM, Adrian Godwin wrote:
> What sort of heatsink does it need ? Do you need the original part or
would
> a lightly-machined generic module do ?
>
At the time, at least in the UK, it was a very common extrusi
Hi
You *really* need to keep the baseplate of the FRK series devices down. Their
reliability drops quite a bit
as you go from 40 to 50 to 60 C on the baseplate. I would avoid boosting the
input voltage without a very
good heatsink ( or heatsink + fan ) setup.
I’ve …. ummm ….. cooked … a number
> On May 2, 2018, at 7:13 PM, Roger Tilsley wrote:
>
>
>
> In my experience, FRK modules produce their best performance when operated
> from a supply voltage between 27 V and 28 V, selected for individual units
> but 27.6 V is a good starting figure.
Would there be any value to designing
Like this one ?
Yes, very common - I'm sure something suitable could be found, if not in my
junkbox then at an amateur radio sale.
http://radioattic.com/images/martin/Martin_Astron_RS-20A_more.jpg
On Thu, May 3, 2018 at 4:37 PM, Dan Rae wrote:
> On 5/3/2018 7:38 AM, Adrian Godwin wrote:
>
>> W
On 5/3/2018 7:38 AM, Adrian Godwin wrote:
What sort of heatsink does it need ? Do you need the original part or would
a lightly-machined generic module do ?
At the time, at least in the UK, it was a very common extrusion, often
used for power supplies etc., and in fact I see two on the back of
What sort of heatsink does it need ? Do you need the original part or would
a lightly-machined generic module do ?
There are some lovely heatsinks in obsolete (server quality) PCs. Huge
chunks of copper with a fine fin structure and a matched fan. Not all of
them are noisy.
On Thu, May 3, 2018 a
Greetings Paul,
The Racal 9475 does have some inherent shortcomings, the principal one is due
to the power supply and the lack of the purpose-designed heat sink for the FRK
module. The unit is built into a “heat-sink case” but to keep the FRK base
plate within the specified temperature range R
They also suffer from all the typical electronic component age related faults.
I had 5 units that had four bad capacitors each, for instance, and after
replacing the caps, they run well.
Regards,
Jerry
> On May 1, 2018, at 6:16 AM, Bob kb8tq wrote:
>
> Hi
>
> Ok, quick intro to Rb standard
On 5/1/2018 2:18 AM, Paul Bicknell wrote:
As I have just bought a Racal 9475 Rubidium and it has problems
Is there any stock faults ?
What is the life of the rubidium standard?
The Racal manual for this only covers the support stuff. Your problem
is almost certainly with the Rb modul
Hi
Ok, quick intro to Rb standards:
On an Rb you have a light bulb. It’s a really weird bulb but a bulb none the
less.
On most (but not all ) designs the bulb has a finite life. Various improvements
over the years have stretched out the life. Just when which outfits did which
improvements …. w
y 2018 10:19
To: time-nuts@febo.com
Subject: [time-nuts] Racal 9475 Rubidium
Hi all new member hear could any of you help with the following information
As I have just bought a Racal 9475 Rubidium and it has problems
Is there any stock faults ?
What is the life of the rubidium standard?
Hi,
There's a copy of the manual at: http://www.ko4bb.com
What are the symptoms?
Angus.
On Tue, 1 May 2018 10:18:35 +0100, you wrote:
>Hi all new member hear could any of you help with the following information
>
>
>
>As I have just bought a Racal 9475 Rubidium and it has problems
>
>
>
>I
Hi all new member hear could any of you help with the following information
As I have just bought a Racal 9475 Rubidium and it has problems
Is there any stock faults ?
What is the life of the rubidium standard?
Regards Paul
___
time-nuts ma
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