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Very minor differences. The board had defiant #'s but all interchange.
Dave

Absolute must while your in there is to bond everything together with solder and a bridge to the vari cap chamber. If you still have that stupid plastic piece in there and it isn't floating around somewhere take it out and throw it away. They did that as a band aid to try to keep the VFO stable. Put a light sig in it and tap around, yep that's it. If it's a "D" model it is easy to make the VFO turn in the right direction. Covered int he Elcon library. Add an Elcon stabilizer to the back of the VFO for major stability. With the Elcon 33 I think it is I run them on 6, 2 and 220 mhz driving Xverters.?
Dave

Hi Fred. I've been trying to make this work for a while. I'm no wizard with computers. Calrad was making kits for filters. All my AM filters are in use. Every one I build gets a AM filter, even the one I use on 220. You can change the selector jumper to use an SSB filter but won't sound the best. You can also just change the jumper to the open slot and jump across where the AM filter would go. You can bring the band width down with a cap and a resister. Just takes time to make it bearable. hi Will be REAL wide band but works! Be sure to diddle your AM oscillator on freq as stock they ran 700 hz off for RTTY. If you have a Timewave 599zx sitting around you can bring your skirts in with it in the audio section. The AM filter was also used in the FT-620. That's the only two Yeasu's that I'm aware of that use the 9mhx IF. I have used one out of another radio with some success. Won't fit perfect but will work. Just look for 9mhx AM or 6kc band width filters.
Dave

Can anyone help? I have many of these and parts. Computers aren't my strong suit. Radio's are fairly easy.
Dave

Easy fix. Replace the grease and the ball bearings. Hardware store, bearing company or auto parts. Standard size. Please let me know if this is going through. I've been trying to get on here for some time but to no avail.
Thank you
Dave
--
Dave Bohlen

Hi
I found this in my files.
Never did the mod though!
Fred
N1DEC

There was one listed on the auction site recently. Might check and see if it's still available.

73 -Fred, N8YX

A while back I ran across a PDF online detailing one ham's analysis of what it would take to convert a '301 to transceive on 10MHz. Looked in the Files section...nada.

Anyone else remember seeing this?

Thanks - 73
Fred, N8YX

Hi Fred.

You are correct that having an AM filter would improve the listening experience. I your case though, given how difficult it is to find a filter and the fact that the 301 isn't general coverage, there are limited opportunities for SWL. Unless you really, really love your 301, it might make more sense to get a portable SWL receiver for around $100. something like a Techsun PL660 or a reconditioned Sony 2001D/2010 (my personal favorites). You'll likely spend more than that on a filter to maybe just listen to 40 meter SW at night?

If you're competent with a soldering iron, performing a capacitor/resistor bypass on the AM slot in the filter board might work, but ONLY if you know what you are doing. I have not personally done this mod myself, so buyer beware..you assume all responsibility for your rig if you attempt this.

Hi Mark,

I also have two after-market filters that mostly have unintelligible writing on them. I <think> one of them is an Inrad/FoxTango (Blue lettering/sticker) 250Hz CW and the other might be a Wilson 6KHz AM with the correct center frequency. At least that's what the person I purchased it from told me. At some point I will sweep them on the spectrum analyzer and see how they look. But it's not a high priority for me right now. I don't run across filters for 301's very often. It's been my experience that CW filters are more available than AM filters. Comparatively speaking I don't think there were that many 301's sold and even fewer filters for them. No one really can really charge very much for them because the radios themselves aren't worth that much..

The rigs (that I am aware of) that used these same filter's (center frequency) were DZ-Kit's original Sienna rig - and they stopped offering the optional filters for sale about the same time that Inrad discontinued them (which was a looong time ago), the Yaesu FT-7b, R-530 (old Galaxy receiver??). So if anyone ever runs across any of these rigs, take a peek inside - you might find gold (in dem der hills).

Dayton/Xenia is next month - anyone going? One can usually find something they are looking for, but you might have to pay more than you want.

I believe that the original Yaesu approach was to jumper the unoccupied AM filter slot to the SSB filter. Resulting in a 2.7 KHz BW on AM Rx. Bypassing using either a cap or resistors will yield a wide-open BW of something like 20 KHz (the IF roofing filter's BW?). Which may be okay... depending on what you're trying to Rx.

Also note, I think in TX in AM mode, the SSB filter is used even if using a cap or resistors. You might want to check your transmit bandwidth in AM mode just to be safe. There's enough splatter on? the bands as it is....

That's an even simpler AM 'filter' than my three resistor proposal. Was it usable, or just too wwwiiidddeee?!

Regards,

Mark, G4FPH.

I also had the CW and SSB filters paralleled.? The AM filter was empty.? I fixed this and put a .01 uF capacitor across the empty AM filter position in mine.

Hi
My old 1977 FT-301D never had a AM filter. I was wondering where I could find one and how to go about
installing one. The filter board just has the stock CW and SSB filters. I can listen to AM shortwave stations on it but
I think with the filter it would be better sounding?
Fred
N1DEC

Jim and the group,

Per notification sent to the group. I have added a folder in the 'Files' section with what information I have here regarding filters. No, I don't speak Japanese either!

Interestingly, the filter board in my FT-301D has UK, after-market units installed in the AM and CW positions. The after-market CW filter is a 250 Hz bandwidth unit, whereas the stock Yaesu part is, I believe, 600 Hz bandwidth. Presently, I have this three-filter board installed in my FT-301, which I have recently finished repairing. It sounds nice on all modes. I have not yet done the ELCON mods to improve the matching around the IF filters.

My FT-301D is still in pieces. I need to re-fit the VFO which I had apart to fix and assemble and install an ELCON replacement digital display board. The filter board in the D has only two units fitted - the Yaesu stock SSB and CW ones. The picture I posted to the folder shows the links needed on the board for the AM receive signal path to pass through the SSB filter in the absence of a dedicated AM one.

One experiment I intend to try on this two-filter board is the trick that is commonly used on Drake TR-7 radio.There's a roofing filter (XF301) on the IF unit, separate to and ahead of the mode-specific / channel filters. XF301 is shown as type '9M20A', so I'm guessing it's 20 kHz BW at the nose. I intend to make up and test a 'dummy' AM filter, comprising a 'T' pad attenuator (500-Ohm Z, 6 dB loss), with 150 Ohm series arms and a 680-Ohm shunt arm. 20 kHz is really way too wide for AM on congested bands but might be usable.


Like you, I am also curious as to the differences between and FT-301D and an FT-301AD. I have never seen the AD variant here in the UK. Maybe the AD just had the last of the model changes rolled-up into the production run. Somewhat like the FT-101F (which, again, I have never seen an example of on this side of the pond) vs. FT-101E.

Regards,

Mark, G4FPH.

atlasstuff <g4fph@...> added folder /AM And Filter Options

did <NOT> ship

I ran across a funny one in one of my 301's.?

I am fairly certain that Yaesu did ship their radios with Trio Kenwood speakers installed..

Pic posted under funny.

I have always been curious as to what the final improvements that Yaesu made to the 301AD that justified a new designation. Or maybe, they were just using it as a marketing ploy to increase sales? Who knows. I would love to hear from someone that was at Yaesu that designed/worked on these radios at that time.

Anyways, I am not that curious as to crawl through schematics for differences, but I did run across one.
- Addtional caps around one of the voltage regulators - perhaps for stability (reliability? noise?) were added. I posted in an album. None of my other 301's have these differences.
The ceramic looks to be 0.047 and the electrolytic looks to be 100 uF (per the schematic), I didn't want to disturb it just to read the value (on the backside). I am considering doing this mod to my other 301's it seems like it might be a good thing to do.

Maybe if others discover more differences, they can post them.

I thought I would post a series of pics showing various CW/AM/no optional filter installations. I was inspired to do for a couple of reasons:

1) I can't seem to find much info on performing filter installs. Perhaps someone can point me to some documentation? I can't seem to find any, unlike the FT-101, which I did find adequate installation instructions.

2) I ran across an example of what not to do. In effect paralleling the SSB and CW filters. I have no idea what this would have sounded like on transmit, but I found it on receive because I noticed that there was no difference between SSB and CW RX audio. Once I corrected it, there is now. I am still working through (fixing) all of the issues for receive on this particular rig (of which there are numerous), before I attempt to TX. I may post more info on that effort in the future. In the mean time, enjoy the pics...