[600MRG] Fwd: Re: Testing new Transmit downconverter

[Dave]

I built a true transverter (ie tx and rx converter) for 474.2khz in my uk
station and I have been very pleased with it

I use the k3 as the IF at 30m and use the K3 10MHz reference as the local
oscillator

I did use it for a while with a good 10MHz oscillator as the LO and still
got decodes

To reduce the size of the LF station I have used the FT817 as the IF on 30m,
but mine definitely needed the onboard histab oscillator to get reliable
decodes

Dave

Ww2r, g4fre

-----Original Message-----
From: 600MRG [mailto:600mrg-bounces at w7ekb.com] On Behalf Of pat bunn
Sent: Thursday, April 25, 2013 8:57 AM
To: 600MRG at w7ekb.com
Subject: [600MRG] Fwd: Re: Testing new Transmit downconverter




-------- Original Message --------
Subject: 	Re: [600MRG] Testing new Transmit downconverter
Date: 	Thu, 25 Apr 2013 09:45:53 -0400
From: 	pat bunn <pbunn at patbunn.com>
To: 	John Langridge <jlangridge at sbcglobal.net>



My experience with transmitting down converters is not all that good -
actually bad. They are easy to make from scratch, but the problem is
with stability in the transmitter or transceiver. I found my IC718 to be
worthless for WSPR, especially WSPR-15 even at 1 watt output due to
thermal heating causing significant frequency drift. I think Dex also
had the same problem with a newer ICOM tranceiver.  The IC718 set at one
watt out got physically hot to touch after a 15 minute WSPR transmission
and was impossible to decode by Dex,  80 miles away( a very strong
signal) due to drift

They are probably fine for CW, but for long QRSS or other long transmit
modes, you are likely to be disappointed.

After testing several different methods to stabilize the transceiver, I
bought a used HP signal generator to generate my transmit signal to feed
the class D Amps. I have this GPS disciplined and am very happy with
this solution.


Pat
WG2XCT
N4LTA






On 4/24/2013 8:47 PM, John Langridge wrote:
> First of all, let me say thanks to all of the stations that continue to
listen
> and transmit on 630m as the days seem to get longer at an alarming rate
and
> noise keeps going up.  The last month has been brutal here in NTX but the
last
> few nights have shown some improvements.  Thanks again!
>
> Tonight I am testing a new transmit down converter developed and kitted by
John
> Molnar, WA3ETD/WG2XKA.  The kit is pretty sweet, with a minimum of parts
and
> appears to be capable of producing close to 20 watts using an IRF510 at
13.6v
> and around 2 amps.
>
> SO far I really like what I am seeing.  Anyway, I will be testing it
tonight but
> plan on letting it run in some capacity over night, whether as exciter
only or
> driving the amp, I have not yet decided.
>
> 73 and again, thanks for listening!
>
> John KB5NJD/WG2XIQ
> _______________________________________________
> 600MRG mailing list
> 600MRG at w7ekb.com
> http://w7ekb.com/mailman/listinfo/600mrg_w7ekb.com
>



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