Yes it's the first stage,I should have the next stages w/ discriminator real soon.
One of the new components for oscillator circuit, the trimmer capacitor can be adjusted above board which really helps on the RF alignment. Thanks
Yes I am seriously considering it, there seems to be a huge intrest today in Dynaco gear, and the FM-3 is gaining on the other Dynaco products. I would hope enough intrest to begin manufacturing of the parts that are hard to find such as the IFT's needed for tube tuners.
You'd have no competition as far as I know so this could be a viable business. No question that these boards would make for a more stable and predictable tuner over time. Taming thermally induced local oscillator drift was a challenge in the original design, presumably you have kept the original ceramic caps or replaced them with devices with the same tempco. (Potentially some minor tweaking required here.) FR4 or G10 should be a lot less hygroscopic than the original phenolic pcbs and less lossy which hopefully result in somewhat improved overall performance. Definitely looks a lot better which is good enough justification IMHO, and the other new parts should help stability as well.
There's a fellow in Germany that makes IF "cans". The PCB versions look like rectangular blocks. Nothing unusual about that. The P2P versions are cylindrical, with a wedge on top that holds everything together. IIRC, the coils for the P2P versions are mounted on PCB material which sticks through a slot in the shield and an opening in the PCB material is what the wedge engages.
Yet another method for dealing with the IF interstage trafo issue is a parafeed setup, with a RF choke loading the plate and a DC blocking cap. coupling the plate to a reverse connected (step up wired) BJT IF "can". The Mouser catalog page for BJT IF trafos is here.
I will have some PC-8 boards some time at the end of next week, I have already done PC-12,so I will have a FULL set,some already populated,I could work an exchange,old for the new,which will lower the cost,plus give me the components I need to populate the new boards. I can PM you when I get those in,Thanks.
Here is PC-12. When I was first working on the design,I was using the old board as a pattern,so I didn't design the new board to accomidate individual components for the PEC filters,although I know there are modern PEC modules available,I just decided to use the old. In the newer design I will make space available for the PEC components.
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Wow, looks very nice.. Unfortunately I don't have an FM-3, I will however tell some of my friends about yours.
Sounds good,I already have several boards populated already,but I can supply you with a BOM. In addition to resistors and caps,I have only made two other changes in replacement of the old components.
PC-7 C8 has been replaced with an Air Dielectric Trimmer Capacitor made by Sprague Goodman Part No.GAA10006
PC-7 L2 has been replaced by a choke made by Fastron Part No.
MICC/N-3R9J-00
I will PM you the BOM's
Thanks again.
PS In the original design,I simply used the old boards as a pattern,so PC-12 doesn't accomidate the individual components for the PEC filters,so I am updating the design for that.
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Wow, looks very nice.. Unfortunately I don't have an FM-3, I will however tell some of my friends about yours.
I appreciate it!!
Your boards look really great and should be good for those who only wants to partly restore their Dynacos.
I don´t want to be rude but this is the SOTA board sold and made by FM3ZONE:
MOTHERBOARD
Great guy, I have bought many, normally obsolete, FM1 and FM3 parts from him. He has all coils and also new PEC-modules and a upgrade PSU. This could be of interest for those who wants to use your boards.
I don´t want to be rude but this is the SOTA board sold and made by FM3ZONE:
MOTHERBOARD
Great guy, I have bought many, normally obsolete, FM1 and FM3 parts from him. He has all coils and also new PEC-modules and a upgrade PSU. This could be of interest for those who wants to use your boards.
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No worries. Yes He's a great guy,I've bought from Him too,I've seen His Motherboard, He has really done His homework when it comes to the FM-3.
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