I've made a small Web page describing what happened when I changed the
puck antenna on a Rapco 1804M for a more sensitive one. The Rapco 1804M
expects a big outside antenna.
http://www.satsignal.eu/ntp/Rapco-1804M-notes.html
This page has now been updated to provide a comparison between
Assuming it's using a timing-optimized receiver, the lack of a clear
view to the sky is probably the biggest problem. Once they have a
valid almanac, they will normally select the satellites with the
highest elevation angles - and if you have an obstructed view that
might well include several
Assuming it's using a timing-optimized receiver, the lack of a clear
view to the sky is probably the biggest problem. Once they have a
valid almanac, they will normally select the satellites with the
highest elevation angles - and if you have an obstructed view that
might well include several
Jose Camara-Berkeley Nucleonics has them, Keithley has them, they all must
come from the same Chinese OEM. Maybe the quality is good, maybe the specs
are honest and apples to apples. Or maybe not.
---
Interesting to note that the
A couple more :)
http://www.acquitek.com/u6200a/counter-test-measurement.html
http://www.ptsyst.com/U6200A-B.pdf (even with 20GHz input option)
Similar thing I found some time ago when looking for an electronic load.
Same thing with several different branding, price ranging for 1 to 2.
Yes, that in consistent with what I'm seeing, Pete, thanks. I am told that
the actual receiver is a Trimble SVeeSix, so why I occasionally see eight
reports from the Rapco firmware I don't understand.
Ah, I didn't realize this was based on the Trimble board - I was
having a mental seizure and
If anyone was ever to review such a device the actual power consumption would
be usefull to know. The likely savings in electricty costs could provide some
justification for replacing one of my HP5370B's (:
Devices that could also easily run from a DC power source could have merit as
well.
Ah, I didn't realize this was based on the Trimble board - I was
having a mental seizure and thinking it was using a Motorola OnCore,
as so many of the others did. Are you really sure it is an SV6?
Trimble also made an SV8 timing that was in the same form factor and
if it was using that it
By the way, this doesn't mean that the GA-27 is a poor antenna design,
it's just not the best antenna choice for this situation.
The GA-27 is intended as an external antenna for Garmin's handheld
receivers, which normally operate with passive patch or helix
antennas. So the receiver itself needs
I tried a similar Garmin antenna with my Datum ET6000 and the lock times
were really long, even with the antenna on a 14 foot pole above the
roof. I attribute a lot of this to the long 8 ft RG174 style coax
pigtail. I have to wonder if the gain of the preamp as published
actually includes the
The ET6000 used Trimble Bullet antennae when I was selling them in the UK. I
seem to remember about 35db of gain in that antenna.
Rob Kimberley
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Joe Leikhim
Sent: 02 November 2011 18:52
So easily a 20 dB shortfall. I will look out for a similar antenna. Thanks
On 11/2/2011 5:01 PM, Robin Kimberley wrote:
The ET6000 used Trimble Bullet antennae when I was selling them in the UK. I
seem to remember about 35db of gain in that antenna.
Rob Kimberley
-Original Message-
Hi Rob I picked up a couple of mushroom shaped (white flat top rounded
edges prob 70mm diam.) antennas with a small right-angle bracket and a TNC
connector (5v supply) no nameplate but they seem to work fine on 20 feet of
RG-58.
The manual for the 1804M says its an 8-channel receiver and I
While looking for something else I stumbled on an eBay seller in Hong
Kong offering five 113°C thermal fuses for $6 including shipping, which
seems like a reasonable deal...
Item number:130579771801
Usual disclaimers apply, and before anyone complains, yes, it's a
generic photo.
Dan
These look like the ones I got from Mouser or whom ever. They look
different from what I got from Agilent. The ones from Agilent are smaller,
about the size of a 1/4 watt resistor, short leads, pre-bent, to allow them
to 'plug' into the PC board of the 10811. Cutting the leads and
'pre-bending'
re my last, suggesting it was an 8ch GPS.. I have just realised I was
looking at the Rb version manual not the OCXO version which does have a 6ch
receiver. (at least on the manual version I have )
apologies ...put brain in gear before etc.
Alan G3NYK
- Original Message -
Joe, I had forgotten that it is a tight squeeze in there, so yes, they
may be too big to fit easily!
Dan
On 11/2/2011 2:59 PM, J. L. Trantham wrote:
These look like the ones I got from Mouser or whom ever. They look
different from what I got from Agilent. The ones from Agilent are smaller,
OK. I am now in my shop and I have the items in my hand.
I got the replacements from Allied. They are marked '141 degrees C
D139ZPXL'. I think they were NTE. They are 4 mm dia., 13 mm long, and the
leads are 1 mm dia.
The HP/Agilent parts are marked 'UMI 1A 250V 115 degrees C'. They are 2
Next time I have the unit open I will take a look. Are there obvious
markings to distinguish the boards (it's a board and not a box), as I recall
looking but no seeing any.
It's been a while, but from what I remember the boards look almost
identical - the standard configuration has a part of
Update -
I attempted to look at the analog signal. I looked at the output of the
crystal. With the scope's low-pass filter turned on I was able to see a
very weak sine wave with a period of roughly 15us. It was too weak for any
analysis.
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