FT-301 conversion project

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FT-301 conversion project

Post  N8YX on Sun Jul 21, 2013 6:57 am

Going to throw this one out here as a blow-by-blow of what I'm up to with these rigs, then as a request for help.

Everyone who's familiar with my shack knows I'm a huge fan of twins. TR7/R7, TS-820S/R820, IC-751/R71 to name but a few. So why didn't Yaesu keep going with the concept after the FL-101/FR-101?

I'm here to rectify that.

The Project:

After performing an in-depth comparison of the FT-301 and FT-901 transceivers I noticed a number of similarities, especially in the filter, front end and related boards. Even more apparent was the identical conversion and mixing scheme, albeit with a 9.000MHz IF ('301) vs 8.9875 ('901).

Now...the '901 incorporates a number of QRM-fighting features that the '301 doesn't. APF, IF shift and a notch function on the IF board itself rather than an always-on, capacitor-tuned implementation. But the receiver-centric circuit cards are the same form factor, they use the same supply/control voltages...the light bulb went on: If one rips all of the transmit-path boards out of the '301, subs their '901 equivalents and makes provisions for front panel controls, one could create a decent little receiver.

There's more. The RX-only setup now has room for two (count 'em) filter boards. This gives filter selection options of 6/2.4/2.1/1.8/0.6/0.3KHz (w/ 8.8975MHz IF) or 6/2.7/2.1/1.8/0.5/0.25KHz (9.000 MHz IF).

Plan is to build one receiver with the OEM 9MHz IF and another with an 8.8975MHz IF and convert their paired transceivers to match the IF schemes, thereby allowing for correct frequency tracking. HET crystals, BFO/PBT crystals and MCF assemblies have to be swapped around but I managed to source all of that stuff through Ten-Tec, Yaesu, eBay and Inrad.

I'll have one analog-readout pair and one digital-readout pair when done. The digital pair will probably be the one retaining a 9MHz IF as I won't have to alter the counter premix circuitry.

Which brings us to the last part.

These rigs are ham-band only. Current thinking is to build up one for SWBC use and install the spare '901 FM board which is kicking around the shack. There is no room for an FR-101 style 6 or 2M converter (and the IF is wrong...) but receiving converters could be controlled via a front-panel function. I'll use only one IF Filter board in this setup (6/2.7/2.1) and have the option to easily swap a spare Filter board in and out should I wish to change bandwidths on the fly.

Help Needed:

Rather, radio wanted for the SWBC conversion. I'm looking for one or two junker FT-301S (10w analog version) transceivers. Non-operational is fine as long as the mechanical portion is sound and the covers, knobs and so forth are present.

Lots of folks have complete, working, "pristine" stations for sale but I'm not looking to pay "collector grade" prices for something which is basically going to be stripped to the chassis and rebuilt.


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A junker 301S????

Post  KK4ami on Wed Jul 31, 2013 3:40 am

I've been looking for the "cheap" 301S. Is there such a thing? I just want to restore it to normal. I would love to collect all the little 10 - 20 watt radios FT-301SD (just above QRP power). So far a junker 301S seems as easy to get at half price as a very old and used bar of gold!Smile


Last edited by KK4ami on Wed Jul 31, 2013 2:31 pm; edited 1 time in total

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Re: FT-301 conversion project

Post  N8YX on Wed Jul 31, 2013 2:20 pm

I know of a couple for-sale-cheap digital-display versions of the 10w rig but I really need an analog model for what I'm up to. Alas, since the set will be turned into a receiver the 100w PA is useless. For that matter, so is the back panel with the outboard PA mounting hardware. A couple of the rigs sans PA bricks were passed up at Dayton for this very reason.

I'll hit the various Classifieds until I find one, I guess.

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Re: FT-301 conversion project

Post  KK4ami on Thu Aug 01, 2013 2:49 am

If the PAs are good, you can sell them on ebay. I've seen them sell pretty fast and you can cut the cost of the 301S some.

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Re: FT-301 conversion project

Post  N8YX on Sun Aug 04, 2013 7:26 am

KK4ami wrote:If the PAs are good, you can sell them on ebay. I've seen them sell pretty fast and you can cut the cost of the 301S some.
There is the matter of the back panel. I need at least one more of the 10w (no holes) version. It's not just a flat plate - several sections are bent 90 degrees and are used to fasten it to the remainder of the chassis.

I currently have 5 (count 'em) PA bricks in the parts stash and could sell off two. I've offered to trade the back panels from the high-power version to someone who wants to upgrade their low-power set but so far no takers.

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FT-301SD

Post  KI6TG on Thu Dec 12, 2013 6:16 am

I have a Yaesu FT-301SD. Will consider selling or trading.

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Re: FT-301 conversion project

Post  N8YX on Wed Dec 25, 2013 8:06 am

KI6TG wrote:I have a Yaesu FT-301SD. Will consider selling or trading.
That's with the digital readout, correct?

I really need another analog-only version. That is, unless I want to re-engineer the counter assembly to cover the new SWBC bands I'm thinking about incorporating into one of the receiver conversions.

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