The "Sideband Package"

This is a 5-band sideband transmitter built by K8EOP, now SK, probably sometime in the late-fifties to the early sixties. I'm trying to get some provenance on it, as I think it was very well built. It came from his estate, with no paperwork, etc.  Lynn, K5LYN, has discovered that it was originally published in QST, June, '58, as "A Sideband Package," written by George Bigler, W6TEU, and later in ARRL SSB for Radio Am's, 1965.  K5LYN has been kind enough to send my a copy of the 1965 article.   I do now have the original QST, and 2 of the followup "hints and kinks".

Here are a few of the features that you may see in the pix:

1. Very nicely fabricated aluminum enclosure. The legs spaced it above the unit it was sitting on, a DX-100, maybe used as an amp, for air circulation.

2. Various fabricated shields, between tube socket sections, over the RF out jack, across the 455kc filter, over the balanced modulator diodes, etc.

3. Separate chassis for the SB Generator, as in Hallicrafters HT-32/37.

4. Separate chassis/shielding, below, for the VFO components.

5. "Inique" neutralizing capacitor at the 6146.

6. Very neatly handwound coils underchassis, those bunched around the bandswitch are on individual polystyrene rods.

7. VOX control - tho' I haven't figured out how it operates yet.

8. Voltage regulation for the VFO (95v) plus for all other LV sections, (200v).

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The complete tube list is: 6146, (2)12AU7, 6BA6, (3)6X8, 12AT7, 6AU6, 12AT7, 6AH6(VFO), 6CB6, 6AK6, OC-3, OB-3 and an 83 !! rectifier. Here's what I think I've figured out as a rough block diagram (before receiving the article info)---

1. SB Gen has 455kc xtal  filter, a USB/LSB switch, and puts out SB at about 2.5mc. Haven't opened it up to see its scheme.

2. The VFO, 6AH6, puts out 5.2-6.2mc, per the coil resonance, probably it's 5.0-6.0, that works out with the heterodyning xtals later.

3. The 2.5mc SB sig is subtracted from the 5-6mc VFO sig in the first mixer, 6X8, giving 2.5 to 3.5mc which goes to the 2nd mixer.

4. Heterodyne osc. 6CB6, has xtals for the 7, 14, 21, 28 mc bands, xtal freqs. 4, 11, 9, 12.5, in that order.

5. 2nd mixer, 6X8, adds to the 2.5-3.5 : with 4 gives 6.5-7.5, with 11 gives 13.5-14.5, with 9 doubled to 18 gives 20.5-21.5, with 12.5 doubled gives 27.5-28.5. I'm not sure yet how 3.5-4.0 gets made.

6. The proper freq. goes to the driver, 6AK6, which has tuned ckts both in & out.

7. Final stage is single 6146, "multiband tank" with link coupling, with output metering being the only metering in the rig, as in HT-32, etc. Output tuning does not appear to be band switched.

8. I have discovered that several modifications that were published after the 1958 article were made in this unit, so it was probably built after the 1965 "Sideband Manual" was published.

p.s., 11/23/00  I have been operating this rig on 40 & 20m barefoot, at 20-30 watts, and on 20 with a neat H.B. amp made by K9EUI, using 4 807's, with an output of 150w or so.  Give a listen any Wed. nite, on about 14.293 +-, from about 8-8:30 ET, and you may find me there.

p.p.s., 12/03/00 I have been in touch with several other hams, one, Ed - W1RHN, who built it and still has it, and several others who had started the project, but never completed it. Ed finished his in the late '60's, and according to K1HC, who has seen it, it's beautiful. I hope to get an on-the-air meeting between the 2 rigs.


Al, W8UT
New Bern, NC
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