Re: [drakelist] R4-C versus SPR-4 crystal frequencies and others

[DAN COTSIRILOS]

The SW-4 uses the same offset as the SPR-4. I plugged a R-4C cb crystal in the SW-4 and it was so close I didn't even have to adjust the skirt! Beats me why they make them different the dial can more than make the difference anyway! Alot of stock crystals are off that much from each other so why even list 2 different kinds?  Dan ----- Original Message ----- From: Herbert Schulz To: [EMAIL PROTECTED] Sent: Thursday, February 12, 2004 1:16 AM Subject: [drakelist] R4-C versus SPR-4 crystal frequencies and others Hi all, 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