[600MRG] LF: Re: [rsgb-lf-group] Bad news / help request

[N1BUG]

Hello Rik,

Being able to set tone spacing to 100x could help me but I don't
think it is worth to do for one person!

I have no problem to receive. I don't use the same equipment for Rx
and Tx. Only the Tx equipment has drift problems.

73,
Paul N1BUG


On 1/1/19 4:58 PM, Rik Strobbe wrote:
> But this will solve only the TX stability problem, you will still need a sufficient stable RX!
> 
> 73, Rik  ON7YD - OR7T
> 
> ________________________________________
> Van: rsgb-lf-group at groups.io <rsgb-lf-group at groups.io> namens Rik Strobbe <rik.strobbe at kuleuven.be>
> Verzonden: dinsdag 1 januari 2019 22:57
> Aan: rsgb_lf_group at blacksheep.org; rsgb-lf-group at groups.io; Discussion of the Lowfer (US, European, & UK) and MedFer bands; 600MRG at mailman.qth.net
> Onderwerp: Re: [rsgb-lf-group] Bad news / help request
> 
> Hello Paul,
> 
> in the current SlowJT9 version double and quadruple tone spacing can be selected.
> If it is of any help I can allow any value for increased tone spacing.
> The practical limit will be the TX bandwidth.
> But for JT9-5 the signal bandwidth is only 2.6Hz, so anything up to 1000 should fit within the TX bandwidth.
> 
> 73, Rik  ON7YD - OR7T
> 
> ________________________________________
> Van: rsgb-lf-group at groups.io <rsgb-lf-group at groups.io> namens N1BUG <paul at n1bug.com>
> Verzonden: maandag 31 december 2018 16:54
> Aan: rsgb_lf_group at blacksheep.org; rsgb-lf-group at groups.io; Discussion of the Lowfer (US, European, & UK) and MedFer bands; 600MRG at mailman.qth.net
> Onderwerp: Re: [rsgb-lf-group] Bad news / help request
> 
> Duh! Scratch item 3. Of course that won't work as it will destroy
> the JT9 tone spacing!!
> 
> Paul
> 
> 
> On 12/31/18 8:59 AM, N1BUG wrote:
>> So, the latest SlowJT9 test is completed. I regret I was not able to
>> run one night on 630m as planned.
>>
>> I used a QRP Labs Ultimate 3S beacon transmitter for these tests.
>> Yesterday I checked my ability to use JT9-5 for QSOs and found that
>> I have none! My FT-2000 transceiver has too much drift to be of any
>> use on JT9-5 and is very marginal even for JT9-2. What a huge
>> disappointment, though it did not come as any surprise.
>>
>> I can think of several ways to solve this but am not sure any of
>> them can save some part of this winter season:
>>
>> 1. Add insulation and a heater to the FT-2000 TCXO area. I will try
>> this but I am not convinced I can make enough improvement. The drift
>> is really ugly!
>>
>> 2. Replace the FT-2000 TCXO with an outboard programmable GPS
>> referenced oscillator, for example a Leo Bodnar unit. The trouble
>> with this is I do not have sufficient knowledge or experience to
>> know what kind of problems might be encountered. The GPSDO is enough
>> of an investment to kill any and all other attempts at a resolution
>> if I am unable to make it work.
>>
>> 3. Use a divide-by-100 circuit with the FT-2000 operating at 13.6
>> MHz instead of a LO/mixer converter from 10 MHz. This should reduce
>> drift to the order of 0.1 Hz, probably quite acceptable. So far I
>> have not found a divide-by-100 circuit using a modern/available part.
>>
>> 4. Run away from the junk FT-2000 completely, using audio to 136 kHz
>> converter for Tx and 136 kHz to audio converter for Rx. This is
>> finally the direction I want to go but there seems to be much
>> learning left to do and a lot of building. It's probably not a
>> solution which can be completed in time for this winter season.
>>
>> If anyone has experience in any of these areas and is willing to
>> share knowledge, please get in touch with me. This may be the last
>> solar minimum for me, and I would like to make some LF/MF DX QSOs
>> before these incredible conditions fade away.
>>
>> 73,
>> Paul N1BUG