[time-nuts] Measurement of frequency of HP 8720D option 1D5 oscillator after switch on

[Magnus Danielson]

Dave,

On 10/05/2014 12:13 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote:
> On 4 October 2014 23:03, John Miles <john at miles.io> wrote:
>>> I just stuck an offer on a SRS 620, which is sold as seen. I'll take a
>>> chance it works if my offer is accepted.
>>
>> The 5370B is still the only high-performance counter that I own, personally.  SR620s are fine as far as they go,
>
> Is it me, or do they look very cheaply made? I have never seen one for
> real, but the photo I see on eBay looked more like a $200 Chinese
> power scope.
>
> I used an Standard Research SR-830 lock-in amplifier extensively
> during my Ph.D. It was really nice to use. But the SRS 620 looked
> rather cheap to me.

Don't judge it on looks alone. While I would have made a few design 
aspects differently, I think it's a rather nice unit and it does perform 
better than the 5370B.

>> but if they have any strong advantages over the 5370 I don't know what they are.  Spending more for a 53230A isn't necessary unless you have a specific need for something that only it can do (and I don't).
>
> I never really looked into it. I just made a low offer on an SRS 620 on eBay.
>
> I am annoyed with myself for selling the 5370B.
>
> I don't really have any immediate need for another TI counter - what
> need I did have, has since gone. But if I could get one cheap enough,
> I would.

If you find a SR620 for a good price, then it's definitly a good thing 
to have.

Cheers,
Magnus