i may have a silly question, but even reading the manuals
carefully several times, i have not been able to find out
what i'm asking for now:
I'm owning an R4-C and an SPR-4 as well. Both appear to have
exactly the same frequency scheme up to the 1st IF-frequency
(PTO tuning range 4955[kHz] to 5455[kHz], 1st-IF frequency
5645[kHz]). For me that leads to the assumption, that the crys-
tal frequencies for the premixer-xtal-oscillator for the
various bands should be absolutely identical in both receivers.
However, in reality, the crystal frequencies in the SPR-4
appear to have a -10[kHz] offset with respect to the R4-C
(i.e. for 80[m], the XTAL in the R4-C is a 14.600[MHz] type
and in the SPR-4 it's a 14.590[MHz] type). Does anybody
know, where this -10[kHz] offset results from? Has anybody
experience in intermixing the xtal's (of course, after placing
them on socket adapters for HC6/U <> HC18/U) for both of these
receiver types?
Furthermore i ask, if anybody has done the majority or all
modifications on an R4-C as documented by VE3EFJ and is
willing to tell me about the experiences? I want to par-
ticipate from any experience before starting this big mo-
dification project, as my R4-C actually is in an absolutely
unmodified, original condition.
Additionally, i'm looking for some parts to buy:
- SPR-4: crystal calibrator, model SCC-4.
- SPR-4: transceive adapter, model TA-4.
- R4-C: 8-pole-crystal filter for AM, frequency 5645[kHz] (may
be of the same type
as for the R7/R7A, but i don't
know that for sure).
- MS-4 speaker in mint condition.
- FS-4 frequency synthesizer.
If somebody has something to offer, please let me know (if
possible, including the approximate estimated shipping charges
to Germany).
Latest: Does anybody know, if there is a GOOD (i.e. low phase
noise) DDS-based frequency synthesizer for the R4-C/SPR-4 etc.
on the market? I'm looking either for a well documented sche-
matic, or a kit, or a affordable ready-to-use unit. The only
thing i found regarding this item is a japanese home page,
but besides the schematic and the photo's, i - obviously -
did not unterstand one word.
This was a lot of stuff - thank you all for your attention and
patience. Thanks in advance for all your answers and respon-
ses and the associated efforts.
vy73, DG7MCC
Herbert
