More likely to need a bit more feedback? try some capacitance ~30pF? from
base to emitter or base to collector. Or across other oscillator
components. It may kick-start.

Sent from Chris McW's iPhone
Amateur radio callsign: G?MQW


On 13 Aug 2012, at 13:41, woodiescbj <jobaco@...> wrote:



Hi, has anyone else built this one? I can not get the Xtal to oscillate all
componants are in the right place with values checked and correct, no dry
joints or solder splashes, number of turns on L1 maybe need adjusting?

Any ideas please.

73 de Colin DD5CF

?

Hi, has anyone else built this one? I can not get the Xtal to oscillate all componants are in the right place with values checked and correct, no dry joints or solder splashes, number of turns on L1 maybe need adjusting?

Any ideas please.

73 de Colin DD5CF

I have a Trimble ACE iii GPS module that I'm trying to interface to the Ultimate Multimode kit.

I have put the NMEA output from the GPS through a MAX233 TTL to RS232 level convertor and fed that to the NMEA input pin on the kit as the GPS outputs NMEA at CMOS TTL levels.

I'm not sure what polarity and signal level the PPS signal the kit is looking for on the kits PPS input pin. I have tried wiring the PPS from the GPS direct to the kits PPS input pin, however it doesn't work (kit in TEST mode and no freq displayed).

The polarity of the PPS signal from the Trimble ACE iii GPS as standard is an inverted 10&#956;s negative going pulse with the falling edge synchronized to UTC.

Should the PPS signal fed into the kit be a positive pulse or negative? I have read that i can use a 10k pull up resistor to make it a positive pulse.

If and when I get it all running I will document it and place the details in the files area.

73 de Colin G1IVG

David,

The incorrect locator has been corrected in Firmware release 1.04. You can
order this from the shop.

73s Steve

On 12 August 2012 11:14, David Barber <david.barber@...>wrote:

**


Hi Colin,

I'm just putting together some info after experiments yesterday but
briefly:

QRSS Firmware V1.02

GPS board is Sure Electronics GP-GS010. (Just because I had one)

Gnd (QRSS) to Gnd (GPS)
+5V Pin 1 (QRSS) to +5V (GPS)
Data In (QRSS) to Data Out 5V CMOS Level (GPS)
1pps In (QRSS) to 1pps Out 3.3V CMOS Level (GPS)

Power to QRSS +5V Supply pin.

"Use GPS" to On
"GPS Baud" default of 09600,01,1,8
Set "Locator" to OO00

Running QRSS in test mode on start, once GPS had acquired signals, it
showed
and updated frequency next to "Test" on the display.

When checking through Menu. Locator had updated but incorrectly (as
expected) to show JO91, should be JO01. Time was correctly shown.

1pps signal is true / high.

Regards

David
G8OQW
***


-----Original Message-----
From: QRPLabs@... [mailto:QRPLabs@...] On Behalf
Of
G1IVG
Sent: 12 August 2012 10:42
To: QRPLabs@...
Subject: [QRPLabs] 1pps signal from GPS to the Ultimate kits 1pps input **
help **

I have a Trimble ACE iii GPS module that I'm trying to interface to the
Ultimate Multimode kit.

I have put the NMEA output from the GPS through a MAX233 TTL to RS232 level
convertor and fed that to the NMEA input pin on the kit as the GPS outputs
NMEA at CMOS TTL levels.

I'm not sure what polarity and signal level the PPS signal the kit is
looking for on the kits PPS input pin. I have tried wiring the PPS from the
GPS direct to the kits PPS input pin, however it doesn't work (kit in TEST
mode and no freq displayed).

The polarity of the PPS signal from the Trimble ACE iii GPS as standard is
an inverted 10&#956;s negative going pulse with the falling edge
synchronized to UTC.

Should the PPS signal fed into the kit be a positive pulse or negative? I
have read that i can use a 10k pull up resistor to make it a positive
pulse.

If and when I get it all running I will document it and place the details
in
the files area.

73 de Colin G1IVG

Hi,
Re the crystals.

I get my crystals from Krystaly in the Czech Republic
www.krystaly.cz

Re the spec of the crystals
You may want to specify some more parameters, to obtain a better product.
Preaging is definitely worth having, as that will reduce early aging drift.

Frequency 14.097100 MHz
Mode:-Fundamental
AT Cut
Crystal loading 30 pF
Holder HC49/u (Wire in)
Preaging +/- 1ppm per year
Temperature range -10 to +60
Temperature Stability +/- 10 ppm
Calibration +/- 10ppm
ESR ~ 20 ohms
Quantity...

Notes:- Ask for quote/ price break and payment methods, as I am unsure of European costings.

I get about 6 crystals (usually different types) on average per order as there are other bank costs associated with tranactions from NZ

I use them both for professional and ham projects. The products are very, very good and very cost competitive with local Australasian product

Another point to consider, is if you want better stability, is to run the crystal with a simple oven, in that case the spec will be different and one has to decide on an operating temperature, instead of temperature range.

This would make the GPS applied correction, easier.

Note:- Logic gate oscillators do stress crystals quite a lot, and is not optimum for stability due to a number of issues.

Kevin
ZL1UJG

?

Guys,

I have programmed and packaged all of the ordered upgrade chips and will post them on Monday. Thanks for your patience.?

73s Steve