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Re: [VHFcontesting] [VHF] Warmup Drift Of Ukranian , UT5JCW, 222 MHz Tra

To: peter h <n6ze@aol.com>
Subject: Re: [VHFcontesting] [VHF] Warmup Drift Of Ukranian , UT5JCW, 222 MHz Transverters & Possible Use With FT-8
From: JamesDuffey <jamesduffey@comcast.net>
Date: Fri, 16 Apr 2021 09:16:40 -0600
List-post: <mailto:vhfcontesting@contesting.com>
Pete - I am not sure my replies are getting through to the reflector, but Keith 
is right, the biggest problem will be the drift when the transverter is 
transmitting. 

Here is an article which quantifies tolerable drift for the various WSJT modes. 
It suggests that drift of 0.5Hz per second is tolerable. 

< https://w3sz.com/W3SZ-VHF-UHF-uWave-NewDataWhichJTModeNew4-3-19.pdf >

If this does’nt hit the reflector in a reasonable time, can you post it for me? 
- Thanks - Duffey KK6MC 

James Duffey KK6MC
Cedar Crest NM

> On Apr 16, 2021, at 08:32, peter h via VHF <vhf@w6yx.stanford.edu> wrote:
> 
> 0715pdt 16april2021
> A number of us in SoCal have been using UT5JCW's 222MHz transverters with 
> good success on CW/SSB/FM from home and hilltopping/roving.
> Tim, N6GP, wondered if they are suitable for use on FT-8.
> Steve, WA6EJO, 'volunteered' to plot drift data on his UT5JCW 222MHz 
> transverter.
> His results are tabulated below.
>    Steve, WA6EJO, did some transmit frequency stability tests using a GPSDO 
> referenced frequency counter.
>  Some of the drift may be due to the exciter, a TS2000X, but most is from the 
> Ukranian transverter. 
>  From 2 to 3 minutes after power on it moved -227 Hz 3 to 4 minutes -103 Hz 4 
> to 5 minutes -64 Hz 5 to 6 minutes -45 Hz 6 to 7 minutes -27 Hz 7 to 8 
> minutes -21 Hz 8 to 9 minutes -17 Hz 9 to 10 minutes -7 Hz 10 to 15 minutes 
> +50 Hz 15 to 20 minutes +13 Hz 20 to 25 minutes +47 Hz 25 to 30 minutes +37 Hz
> 
> 
> Do any experienced FT-8 users have any comments on possible use of the 
> transverters with data modes?
> Thanks,
> BT73
> Pete, N6ZE 
> 
> 
> 
> 
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