[600MRG] Bad news / help request

[N1BUG]

In this case, it is the transceiver. The converter LO is a 10 MHz
OCXO, already good on its own but I put it into a box with lots of
insulation. It holds within .01 Hz for hours, even days.

The FT-2000, on the other hand, moves about 9 Hz at 10.136 MHz with
ambient temperature change of 4 or 5 degrees F. Every time my
furnace runs, the thing scoots up 9 Hz, then slowly settles back
during the cool-down period. In the absence of ambient thermal
cycling, it moves 6 Hz during a 5 minute transmission at 10W RF
output due to its internally generated heat. At the end of the 5
minutes it shows no signs of settling down, it is still moving.

I am able to receive JT9-5 because I don't use this rig for that. I
use a very simple homebrew SDR with a crystal oscillator LO that
holds within 0.1 Hz even without any temperature compensation.

73,
Paul



On 12/31/18 2:59 PM, Michael Mussler wrote:
> I found most of the frequency drift was in the LO of my
> transverter. I replaced it with an input from an external 10 MHz
> reference and used the 30m band as the tunable IF. The rig
> consists of either a K2 or a K3 with the transverter option,
> home-brew transverter using a MiniCircuits passive double
> balanced mixer, and a surplus HP Z3801 GPS receiver/reference
> oscillator. The K3 has the high stability oscillator option that
> gets locked to the external 10 MHz reference. However, the
> stability using the K2 in the set up was adequate for long term
> WSPR operation on 630m. I ran this set up in a marginally heated
> space and > 20 degree F temperature fluctuations for years with
> good results.
> 
> If you have access to a good reference oscillator, give that a
> try in your set up before you write off the TS2000.
> 
> 73 Mike, AI8Z ex WD2XSH/12