[time-nuts] Errors on HP 58503A GPS time & frequency reference receiver bought from yixunhk

Dr. David Kirkby (Kirkby Microwave Ltd) drkirkby at kirkbymicrowave.co.uk
Fri Dec 12 05:36:16 EST 2014

On 12 December 2014 at 03:54, Peter <timenut at exemail.com.au> wrote:
> Hi David
>> "The fact it does actually work, probably indicates there's nothing too serious wrong with it."
> In my opinion, you potentially (pun intended) have a very serious problem.  Your LOG shows the 15V supply rail out of tolerance at 19.46V.  That is, nearly 30% high - it could be even higher at other times.  This should never happen.  Such excesses may permanently damage board components.  Do not tempt fate - power off the equipment immediately before it self-destructs.

I did consider that possibility. It does however appear to be working
ok. The log looks ok now, it is locked to gps, the output is "about"
10 MHz. I can't check it too carefully. It is agreeing with my
frequency counter that has an 10811A not been calibrated in 20+ years.
I don't yet have the SR620 TI counter I purchased to see how much they

> Replacement of the PS brick may be required and while they are available at reduced prices they are not inexpensive.

Yes, I noticed that.

> You have purchased a non-functional fake and I would instigate action to recoup my payment.  I regularly purchase electronics out of China via eBay/PayPal and fakes are everywhere.  My policy is to never return fakes ("it is against the law to post fake items" and in any case they are worthless - particularly if they are faulty) and demand a full refund.  While this may require some effort in communication, PayPal has always come to the party.  In my opinion, if you return fakes they are simply on-sold to other victims.

It would be next to impossible to prove this is a fake. If it was a
current, or fairly current Keysight product, they might take a look
for nothing. But Keysight are not going to want to get involved about
a product line that HP sold to Symmetricom a long time ago.

I am sure I can convince eBay/Paypal it is non-functional, but
convincing them it is a fake is a completely different matter - not
helped by the fact that people who do get problems tend to keep quite
about them. I got an email from someone yesterday which described the
problems he had, but ended in

"And like the others I chose not to talk too publicly..."

> Yixunhk is well known as an eBay seller who will take you for a ride, both financially and technically.

I'm amazed yixunhk keeps the 100% positive feedback, but I guess if
people don't leave appropriate feedback, it is hardly surprising.
Someone recently emailed me to say they had a problem with a GPS
receiver from yixunhk, but returned it to a US address they were
given, and got a full refund, including the shipping costs. What
feedback they leave is up to them of course. Some might consider that
a positive outcome.

That said, I emailed a friend about this, who has bought from yixunhk
and had no problems - that was on a tracking generator for a spectrum
analyzer - not a time-nuts related item.

> If you are considering a purchase from him, first do your research - Google the blog of fellow time-nut Mark Stephens VK2HMC, and his time-nuts posts.  As another victim, he has a few words to say.
> Peter

Yes, I found VK2HMC's  blog, which just seems a rant about yixunhk,
but does not contain any real substance.


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