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R Pete
Well , its possible to use the emergency vfo , but
that results in a very unstable signal , I
remember down the Tottenham court road , there where tea
chests of crystals , but that was 1970 .. seems a
lot of the traditional firms have closed ,
One of the £5 dds with a driver
would work , but they want to keep it
standard
DS - That's really the 'correct'
situation , that -33 db decode, -3 db lower
than normal was a good indication
that the system is working , over
ranging the a/d is the only problem . I
think dynamic range is 60 d b after processing ,
is it 3 db per bit ? 8 bits , 24 db +
3 that's 27 dB ? 500:1 ? , but
by removing qty 2 mixers
and 2 oscillators , [ may be 3
oscillators 1 , hf-up-conv 2 , pll conv osc 3 ref
osc ) that is a lot of noise + jitter
removed from the signal path as well as
imd from 2 mixers , I found a attenuator
helped for mw and I have a mw-filter ,
which cleaned up sw bands ...... nice
to have a panoramic display , 2 mhz this time ,
the ra17 was 1 mhz and 28 valves + 20 ish
> in the radio
73-G.
Sent: Thursday, April 11, 2013 10:47 AM
Subject: Re: LF: Wanted 10XJ or FT243 XTALS Range 236.25 236.75 KHz
OK Graham
Thought it was home brew retro.......... I am in that mode and think
everbody else is! What do you do at the moment inject a Sig Genny?
Have you checked the net or checked out Vincent - QuartzLab etc?
Anyway what's that master osc circuit. I build from old RADCOM (pre
1975 when they published real amateur radio) and PW,QST etal. I use modern xtals
with no known issues. Well trying to get third overtone for 10m not to chirp is
an issue with me at the moment.
OK yes got a stick on its way didn't want to tear up my existing
upconverter design. But not sure there is much wrong with the UC approach it
works for me. But want to try the direct approach. Do you get much Cross mod and
IM products?
73 es GL Pete M0FMT IO91UX
Ok Pete
Q where to have them made ?
The set , Marconi Ocean span 1950's valve
tx needs the big rock's as the
oscillator pass's quite a lot of
power via them ...hc6u are no good , drive level
is very low - the ones fitted are the wired- gold
flashed ones , so cannot etch into the
band ...
the gang want to keep it standard
73 -G.
Ps waiting for qty-3 £6 dongles :
)
Sent: Wednesday, April 10, 2013 11:43 PM
Subject: Re: LF: Wanted 10XJ or FT243 XTALS Range 236.25 236.75
KHz
Hi
If you want to spend a small fortune get them cut. However build a
Mixer VXO from El cheapo standard xtals and or old PMR rocks. Then at your
next rally buy a couple of Screw together 10xj or FT243 rocks of any frequency
and put the El-cheapo xtals inside. And Hey Presto you have Retro
rocks.
I have a small all valve 472 tx that uses 6.00 -6.472=0.472
vxo-able a couple of kc/s 12ax7-6am6-6cl6= 4wattso/p. Local QRP
rig.
Hope this helps
73 es GL Pete M0FMT IO91UX
Wanted 10XJ or FT243 XTALS
Range 236.25 236.75
KHz
Q Is there any manufacture of
crystals in this range ?
Or Surplus items available
QTY 1 or 2 off
TNX- Graham
G0NBD
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