[NLRS] Latest on 10m Rx/Tx Softrock!!

[Bill K0AWU]

Hot off the press today Dec 16,2007


Progress is being made on the 10m Rx/Tx, not yet "prime time" but we see 
that things are indeed moving forward. See the notes from Tony below. I at 
this moment am not interested in a prototype. I just don't have the test 
equipment to evaluate it. So I'm waiting. Xtal expense is a concern to me. 
It this point I don't know the freq required, but all custom xtals are $$$$ 
any more. If mass produced xtals can not be found, maybe a "large"buy can be 
made. Being a "proto typer" could cost one around $100. Don't let the 
sensitivity scare you ... you will have or have to have 28mhz gain ahead of 
the receive side. I sure had to have that for the original Ver 7 10m 
Softrock rec as well as with my SDR1000.

See below ... Bill  K0AWU



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Bill Dumke, WA9PWR, has been testing the 10m prototype RXTXv6.2 unit.  Bill 
was able to get crystsls for the two center frequencies you list below from 
International Crystal.  (At least, I think that was the crystal source. For 
28.100 and 28.200 "center" freq)

A summary of performance of the prototype reported by Bill is as follows:

1) RX sensitivity at about -120 dBm in a 500 Hz BW
2) 1 watt output with carrier, TX image and harmonics down at least -43 dB
3) PSK31 IMD products down about -20 dB at one watt output

I have ask Bill to check the PSK31 IMD products at a reduced power level 
since the 15m RXTXv6.2 prototype showed a 5 dB improvement in PSK31 IMD 
products when the power output was reduced from 1 watt to 0.5 watts.  (The 
PSK31 IMD products are down slightly over -30 dB in the 15m prototype at 0.5 
watts output.  Typically the PSK31 IMD products have increased as the the 
RXTX was tested at each higher frequency band, 20m was not as good as 40m, 
etc.)

I think the 10m RXTXv6.2 kit could do with more field testing but I would 
like to hold down the number of kits shipped until the design has received 
additional testing.

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 I am thinking about a limited beta run of the 10m RXTXv6.2 kit with
the daughter board kit to get additional field experience. Please
let me know if you would be interested in helping with additional
testing. The kit would be provided less the 10m crystal and would
require the kit builder to order his own crystal. I would need a
payment of $35 from each beta testers to help with the expenses
associated with the kit and mailing.


Thanks and 73,
Tony KB9YIG         raparks at ctcisp.com