[time-nuts] Loran and SRS FS700 in the UK

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 11 Jul 2015 03:28, "GandalfG8--- via time-nuts" <time-nuts at febo.com>
wrote:
>
> This is a reply to the topic "Loran-C reception in the UK" with specific
> emphasis on the Stanford Research FS700.

> Points to note.....
>
> All three of my units seem to have the Option 01 oscillator fitted,
> although only one states this on the option label, so perhaps this became
> standard with later production. I don't know and wouldn't take it for
granted  but
> thought it worth a mention. The fitted oscillator in each unit is an
> identically specified SRS SC10.
>
> Mine are off air right now as I swap about stuff in the timing rack,  and
> haven't really been run for much more than initial tests, albeit for quite
> long periods. My general impression so far is that the reported frequency
> offset  might be a bit optimistic, this is compared with Thunderbolt
GPSDOs,
> but I need  to do more work on this.

Useful to know, but of course it could be the errors are on the
Thunderbolts! The problem with having multiple GPS units is that they are
not exactly independent of each other.

> The latest FS700 firmware I have seen is version 1.20.
> I can make the 1.20 firmware available if anyone would like a  copy.

I might take you up on that if I get an FS700.

> FS700s have become available on Ebay at very good prices since the USA
> Loran-C chain was closed down, that's why I have three:-), but it needs
to be
> noted that these are mainly from "recycling" outfits, what we might once
> have  referred to as scrap yards in the UK, and usually untested and with
no
> warranty.

> On average mine have cost me about 200GBP each, including shipping and
tax,
>  but beware of some sellers still asking anything up to 1000USD before
> shipping  and import tax.

I have never seen them at anything like the price you see. About the
cheapest I have seen is $600. I did notice one or two on eBay that are
rusty, which struck me as odd.

> That small mains transformer runs really hot, not too surprising perhaps,
> and I've seen at least one online photo showing two larger transformers
> mounted  in the space towards the front of the unit. One or two probably
depends
> on  what's to hand but I would suggest a very worthwhile change. Mains
> voltage here  is generally over 245 volts, so a bit on the high side, but
I do
> believe that  transformer is underrated.

Are there multiple secondries? If not getting a replacement should not be
hard but otherwise it could be tricky.

I know someone who run his whole house on an autotransformer because his
mains voltage was too high.

> Small point, but a nuisance, there's no backlighting on the LCD  display.
>
> Overall impression, an excellent unit with programmable output frequency
> and built in phasemeter, and I can't wait to get mine back on the air:-)

If I could get one for £200 imported into the UK I would definitely get
one. I thought I would need to pay considerably more than that.

I have seen some in Hong Kong and China. I don't know if the system ever
worked there,  but if not then
> Regards
>
> Nigel
> GM8PZR

Cheers Nigel.

Dave G8WRB.