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