Hello to all,

I connected the unit to a 11m of H-155 cable(assumed 4.79dB loss "worst
case" at 1.5GHz), thrown the GPS antenna on the balcony horizontally and
this is what I got:

UCCM-P >SYSTem:STATus?

57964-80    serial number  87896988    firmware ver  2.0.1.6-01
LINK    mode

Reference Status __________________________  Reference Outputs

XX Ref 8KHz 0: [Unusable]
XX Ref 8KHz 1: [LOS]                          TFOM 2            FFOM      0
XX Ref 8KHz 2: [LOS]                          UCCM A Status[ACTIVE]
XX Ref 8KHz 3: [LOS]

ACQUISITION ...................................................[GPS 1PPS
Valid]
Tracking: 4 ____  Not Tracking: 6 ________  Time

PRN  El  Az  C/N  PRN  El  Az                GPS 23:42:46    26 Nov 2016
24  45 139  43    25  57 286
6  24  62  38    19  11  42                ANT DLY  -1 ns
2  30 101  46    32  37 279                Position

29  30 206  41    12  70  37                MODE    Hold
14  26 309
31  8 309                LAT      N 45:40:29.276
LON      E 9:26:51.177
HGT +320.96 m (MSL)

ELEV MASK  5 deg

Command complete
UCCM-P >

Seems to work (? I understand this from GPS phase and FFOM 0, not sure
about the hold position status) I have somewhat stable 10MHz output,
tomorrow I will use a mast for the antenna to get it higher slightly
above the roof, (vertically this time!).

• I got the software from the seller but complains about some ancient
  OCX stuff don't want to mess with ActiveX anymore, hopefully Lady Heater
  will support it soon.

• Given the attenuation (less than 5 dB) do I really need to change the
  cable for something better?

Leds are Yellow Activity solid, red unnamed blinking fast,  Red 1PPS
blinks once a second and DC green is solid.

Anything else special to check?

Giuseppe Marullo

IW2JWW - JN45RQ

PS: the other clock (qrp-labs) is way behind schedule, but hopefully
will arrive soon

`

Hi

For a long term installation, an antenna location that will “see” more sat’s is a really good idea.

Bob

Here is my take on this:  Why worry about a few dB of attenuation in the
cable when you have a 100% blockage problem for half the sky?

With GPS receivers, cable attenuation (within reason) is not important.
What matters is if you can see the satellites or not.  It is more of a
binary on/off kind of thing.  The data is digital, you either get the bits
or not.

So, by my above rule you only need to upgrade the cable if cable
attenuation is such that the signal is close to the receivers sensitivity.
Even then you can usually find a higher gain antenna.  At some point
after maybe 50 meters of cable you might need to consider low loss cable

Nothing in the setup is more important that having an unobstructed view of
the sky

On Sat, Nov 26, 2016 at 6:18 PM, Bob Camp kb8tq@n1k.org wrote:

--

Chris Albertson
Redondo Beach, California

Sure, specs says:

• Amplifier Gain: 26 dB +/- 3 dB
• Maximum Noise Figure:≤ 2.5 dB @ +25°C including pre-selector
  I still have to search a command to check signal strength.

Antenna was on the balcony at first floor (european, 2nd floor us) on the balcony, laid there horizontally. Frankly I was not even expecting it to work at all, LOL!
With a ten feet mast I was able to get eight-nine satellites before having to disconnect it.

A little higher and it should have a perfect sky clearance (a little bit more cable will be needed though, hence the question about length).

Giuseppe Marullo
IW2JWW - JN45RQ

From: "time-nuts" time-nuts-bounces@febo.com
To: time-nuts@febo.com
Cc:
Date: Sun, 27 Nov 2016 07:01:05 -0000
Subject: Re: [time-nuts] UCCM arrived

Hello to all,

I connected the unit to a 11m of H-155 cable(assumed 4.79dB loss "worst
case" at 1.5GHz), thrown the GPS antenna on the balcony horizontally and
this is what I got:
[]

• Given the attenuation (less than 5 dB) do I really need to change the
  cable for something better?
  []
  Giuseppe Marullo
  IW2JWW - JN45RQ

---====

Giuseppe,

Most GPS antennas have an LNA built-in, making cable loss less significant.
Doesn't your antenna have that?

73,
David GM8ARV

SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv

time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.

Hi

You have a system with cascaded gains and noise figures. The “front end” of the GPSDO is
in the antenna. The cable is between the front end of the receiver and the rest of the “radio”.
With a cascaded noise figure situation, as long as the noise figure of the first stage is low (it is)
and the gain of the first stage is high (it is) and the noise of the next stage (in the GPSDO) isn’t
awful (it’s not) there is no problem. The gain of the antenna is specified so you know what that is.
If the cable loss is less than the gain by about 6 db, there is little impact. In this case “little” means
that you can’t measure what the impact is. Since you have a 26 db antenna, the cable loss needs
to be less than 20 db. If you can get it down to 16 db that would give you a bit of margin.

Bob