My HW-101 story begins 45 years before it begins :-)
When I got started in ham radio, I began that journey with a school-mate and friend: sharing Radio Shack morse-learning records, meeting up with local hams, building stuff... and I acquired his used HW-100 as my very-first commercial transceiver in 1976. I used my HW-100 for receive-only; 1977 I got my license and put my HW-100 on-the-air.
In 1979, I packed my HW-100 into a fruit-box and flew to the West Coast for summer work, operating all the while.
I took my HW-100 with me when I went to Queen's University, 1981 - 1986.
My HW-100 was my companion as I moved West, built homes and moved a few times. I bought a Kenwood TS-850, and my HW-100 fell into "backup status"... the VFO was kind of warbly and maybe even jumpy; it languished. When a work-colleague got his ham-license, I gave my HW-100 to him to use...
... and in time I began to miss my erstwhile companion. After all, I'd used my HW-100 for 30 years!
15 years after gifting away my HW-100, I was perusing Craigslist in December 2021, when I noticed an HW-101 for sale. But it was curiously labelled as "...an ideal winter project", and OBO. Intrigued, I contacted the seller, to learn that the HP-23B power-supply had blown up, and the status of the HW-101 was utterly unknown. I took the gamble, and added humour: I offered $101 for this HW-101 with HP-23B and HW-610 speaker :-) I really had not a single clue about what I was buying...
Yeah, this baby was in really bad shape :-( It needed a transformer and thermal-breaker; there were arc-pits on the AC-power-plug blades; there were blackened areas inside; there were arc-pits in the actual housing itself! It was almost impossible to determine WHAT EXACTLY had gone wrong, but the AC primary wiring was involved and at least some of the secondaries were involved in the devastating smoke-show.
At first, I figured I could replace the least amount of components, and get this power-supply running for minimum cost. But as I waited for some parts, and hunted down others, I came to a new place: I opted instead to make this HP-23B the best I could! More than a couple of parts were bought, and I went through a few stages of re-working my re-work to make it the best I could...
Months passed - parts were ordered, delayed, arrived, and the process repeated. Ultimately, I wound up with:
No-Load Voltages:
775VDC Final Plate Voltage
324VDC Screen and other Plate Supply
-130VDC Bias Supply
12.8VAC Filaments
Satisfied that I now had a rock-solid, properly-operating Super-Power-Supply, I could turn my attention to the HW-101.
| Some character-lines, but aging with dignity. The steel chassis shows no rust, despite some paint-chips. Generally, this HP-23B is clean. The chassis shows signs of having had a cover installed at one point, but I am using it cover-less in the SB-600 speaker. Which, by the way, is one reason I chose a grey power-cord: to co-ordinate with the putty-grey of the SB-600. Fashionista :-) |
| With this view of the HP-23B, you begin to see the added mounting-scews for the Gordos Solid-State Relay. |
| Mandatory: a new transformer (because the original/burned one did not arrive with the supply). I opted for a Peter Dahl custom transformer, with Continuous Commercial Service rating (in contrast to Heath's ICAS (Intermittent Commercial and Amateur Service) rating). Perhaps the star of the entire rebuild! |
| Full interior view. See, all my white wires aren't too horrible, are they? The transformer-leads are almost half of the wiring anyway, and they don't match the original Heath colours/stripes. Black Transformer leads = primary windings. Yup, this transformer has two windings, for 120 or 240 VAC operation. I've hardwired it for 120VAC because that's the rating of the SSR, my MOV matches, the plug is a standard 120V NEMA-15P, and my usage indicates that this will only ever see 120. I am committed (or should be :-) :-) ). Red transformer leads = High B+ Blue Transformer leads = Low B+ and Neg Bias Green Transformer leads = 12.6VAC Filament (with unused center-tap) |
| Partial interior view. Here you can see the (yellow-disc) MOV I added for transient suppression. This is located upstream of any switching, so it's active across the AC power whenever the HP-23B is plugged-in. The negative-temperature-coefficient inrush-current limiter is the black disc - it's downstream of the AC power switching, in series with the transformer primary. And the black rectangular Solid-State Relay graces the side wall, where it neatly fits between the chassis top and bottom, as well as neatly between the transformer mounting bolts. I added the terminal-strip for this AC power wiring, relocating all these AC power connections away from the HV / Low-B+ rectifiers and filtering. |
| This partial interior view shows my interpretation of the HV rectification with fewer diodes. Also, both the Low B+ and Bias received the same capacitors, for simplicity of ordering and tons of extra margin. I added another terminal strip to more-securely mount the bleeder resistors (hidden beneath the capacitors) and filter capacitors themselves. All capacitors are labelled, so I have a chance of figuring out what I did, in years-to-come. Or, maybe a future-owner will thank me :-) |
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| This HP-23B (serial 435) starts up quietly, with no magnetostriction "bwang", and it runs without hum or buzz. |
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I had the original Heath cable which came with everything I bought, but the cable was semi-rigid now, featuring the short-inducing metal backshells. This cable embodies "Heath Original".
I subsequently bought a Heath "cable kit" from eBay, which had two new 11-pin connectors, rubber backshells, and some Wireman 8-conductor rotor cable. I built this, then paused... I decided I was uncomfortable with the wire-gauge / ampacity of the included Wireman rotor-cable, also of unknown voltage-rating. And the vendor did say it reflected Heath specifications, so my discomfort then transferred also to the Heath Original cable. :-O
I decided to built my own cable, using wires that were proper and completely appropriate for each task. I selected:
Both the high-strand counts and the silicone jackets were intended to allow flexibility for the finished cable. I find it more flexible than either original Heath, or the eBay+Wireman products. My bundle is 3/8" diameter - about the same size as Heath's but thicker than eBay+Wireman. To retain the flexibility, I used (non-running) lacing... lots of individual pieces and knots.
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| The custom power cable began with cutting 6-foot lengths of each wire, securing them in a dangling position, then lacing. Lacing is gentle on the wires, won't cut me like tie-wraps, and will easily allow sleeving to slip over |
| I began wiring the cable from the plug-end, because it was a bit more-finicky: the 14-ga wire required 10 strands to be cut, in order to reduce the diameter and allow the remaining 31-strands to fit into the pins. The 16-ga AC-switch wires just barely fit into the pin center-holes without any strand-trimming. |
| Braided sleeving slid over wire-bundle, glue-heatshrink applied, and rubber backshell installed. I had to drill out the backshell's internal ribs to accomodate the wire-bundle, and still a couple of tie-wraps help snug the backshell. I've hit the limit for the wire-bundle and this rubber backshell. I opted for Aqua coloured sleeving, because it was about the closest to the HW-101 light green panel colour - always fashionable :-) The Techflex Flexo PET braided sleeving is FMVSS 302 Approved, UL-94V0 flammability-rated, resists lots of chemicals and UV, can operate up to 125degC, and is UL/CSA rated. Not just another pretty face. |
| The Whole Enchilada! That RG-174/U sprouting out the side of the connector backshell is the Relay-Closure, intended to trigger an Amplifier into TX. While I do have an amplifier, I don't really envision using it with the HW-101, but I may change my mind. If I do change my mind, I only have to install an RCA connector onto the RG-174 and I'm in business. The cable was tested in the usual way: jumper AC-switch pins 9 and 10 to turn on the HP-23B, then measure voltage on pins. And it did test good :-) |
I had to open it up, whereupon I found I had replacement silicone belts, bags of replacement parts, and the elusive CW filter!!! Yay!