In this thread, we hack Heathkit's -104 lineup

I got hold of a couple SB614s which are going to be repackaged into Drake 7-line cabinets for use with my TR7/R7, and as I was contemplating the outcome I wondered what others have done with the SB/HW-104 and related components:

• Converted a -104 to the WARC bands?
• Built a full featured receiver from a transceiver?
• Added QRM-fighting features to the rig?

There will be a number of dual knobs and a couple cases left over from these efforts. Inspire me to do something cool with the leftovers, along with a transceiver or receiver (HR-1661).

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Originally Posted by N8YX

Inspire me to do something cool with the leftovers

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Build a laser death ray, man. Everybody wants a laser death ray.

Cool cool coooool!
In for popcorn!

I know I rebuilt the piss poor power supply Heath came up with. They had some MFCsomething ICS driving transistors for the +11 and +5V. I tore all that out and installed LM350Ks in the pass transistor sockets. The MFCs were blown any way. and with the LM350Ks they are bullet proof!

Quote:

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Originally Posted by wa6mhz

I know I rebuilt the piss poor power supply Heath came up with. They had some MFCsomething ICS driving transistors for the +11 and +5V. I tore all that out and installed LM350Ks in the pass transistor sockets. The MFCs were blown any way. and with the LM350Ks they are bullet proof!

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That's good to know. I ended up with an HW-104 with P/S and have yet to get into it.

Quote:

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Originally Posted by kd6vm

That's good to know. I ended up with an HW-104 with P/S and have yet to get into it.

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If you wish to sell, I wish to buy.

Quote:

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Originally Posted by N8YX

If you wish to sell, I wish to buy.

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I have a day off tomorrow. I will pull it out the closet and check it out. See what works and what doesn't.

I'm curious about how you would do the WARC mods. Drop other bands, or is there a way to shoe-horn in the extra circuitry?

12 meters might not be too bad, if you were willing to sacrifice part of 10 meters. 30 & 17 would be more of a problem.

I see a couple on eBeast right now, both in the $300 neighborhood with PS's. One in need of TLC, and one that (allegedly) belongs(ed) to the seller's father-in-law & was last in use a year ago.

Saw those, Ron.

What I'm going to do with 1ea HW-104 and SB-104A:

80-40-20-15-WWV-10A-10B-10C-10D become 80-40-30-20-17-15-12-10A. Who needs the top three 10M segments, considering that most of the operating I do occurs in the lowest 500KHz segment?

What I'm going to do with 2x HR-1680:

80-40-20-15-10A-10B become 80-40-20-15-12-10A and 60-30-17-12-11A-11B (or 11A-10B, etc). These will be slaved to a modified HW-104 and can run in transceive mode a la TS-820S/R-820 or TR-7/R-7.

I'm thinking about converting all of the rigs to an 8.9875 or 9MHz IF. HFO crystals for the various bands will be much easier to obtain than those which are employed in Heathkit's 3.395MHz IF premix scheme and filters of various bandwidths are a little more common as well.

Plans are to incorporate 2.1/2.4KHz (wide SSB RX; SSB TX), 1.8KHz (SSB Narrow), 500HZ (CW Wide) and 250HZ (CW Narrow) onto a redesigned Filter/BFO Board. I think SMT will be used to free up space for the extra filters.

Also looking into front-end redesign and a digital version of the SB-644.

ETA: And the creation of an "SB-624". Envision one of those, if you will...

Got hold of an HFO board, IF/AF board and a bunch of miscellanii for the SB project. An HR1680 is sitting on my shack floor and an HW-104/PSU (courtesy of Ralph) is inbound.

Need the following crystals in either HC/18-U or HC/6-U form factor if anyone has them; all frequencies in MHz:

13.895
18.895
26.895
33.395
35.395
35.895
36.395

Also received four display conversion boards from The Heathkit Shop, a local outfit run by Mike, WB8VGE. These ought to address the noisy display issue which the SB-104 often exhibits.

I'm in search of an SB-604 speaker; condition doesn't matter - and as long as the two black trim strips on its front panel are in good shape, the rest is immaterial. This unit will ultimately be turned into a synthesized remote VFO.