Quick recommendation: When 40 metres is the mission, use the radiator-matched direct-feed coil: CHA SS17 + CHA M-COIL or CHA SS25 + CHA M25-COIL. Choose URT1 for automatic multiband matching, HYBRID-MINI for rugged passive operation, HYBRID-MICRO for minimum burden and the Classic 4:1 arrangement for historical fidelity or existing equipment.
Search cross-reference: URT-1 and URT 1 mean URT1; M COIL/MCOIL mean M-COIL; M25 COIL/M25COIL mean M25-COIL; and SS 17/SS 25 mean SS17/SS25. These spelling variants do not alter the required pairing: SS17 + M-COIL, or SS25 + M25-COIL.
Thirty-Second Selector
| Priority | Recommended architecture | Why | Main compromise |
|---|---|---|---|
| Best dedicated 40 m path | CRY-05A / CRY-05B | SS17 + M-COIL or SS25 + M25-COIL | Coil must match the radiator; requires configuration change for broadband use |
| Fast automatic band changes | CRY-04 URT1/URT1-MB | Match occurs at the feed point | Cost, DC power, mass and duty-cycle limits |
| Rugged passive and higher SSB power | CRY-02 HYBRID-MINI | MPAS-derived broadband architecture | Compatible tuner normally required for fixed-length use |
| Light POTA/SOTA or QRP package | CRY-03 HYBRID-MICRO | Lower packed burden | Lower power and thermal limits |
| Common historical arrangement | CRY-01 Classic 4:1 | Closest Chameleon reference to the published recipe | Real UNUN, tuner and coax require complete-system evaluation |
Compatibility Matrix
| Component | CRY-01 | CRY-02 | CRY-03 | CRY-04 | CRY-05A/05B |
|---|---|---|---|---|---|
| CHA 4:1 UNUN | Required | No | No | No | No |
| HYBRID-MINI | No | Required | No | No | No |
| HYBRID-MICRO | No | No | Required | No | No |
| URT1 + URT1-MB | No | No | No | Required | No |
| M-COIL / M25-COIL | No | No | No | No | One required according to radiator |
| Station/external tuner | Required | Normally required | Normally required | No; URT1 matches | Normally no after adjustment |
Signal-Path Diagrams
| 40 m branch | Radiator | Required coil | Standard feed |
|---|---|---|---|
| CRY-05A | CHA SS17 | CHA M-COIL | Direct Basic Vertical feed |
| CRY-05B | CHA SS25 | CHA M25-COIL | Direct Basic Vertical feed |
Configuration Parts Lists
CRY-01 Classic 4:1
- CHA SS25 and compatible mount
- CHA 4:1 multiband-vertical UNUN
- Selected Chameleon radial/counterpoise system
- Compatible choked coax
- External or station tuner with sufficient verified range
- Approved guying and analyzer
CRY-02 HYBRID-MINI
- CHA SS17 or SS25 and compatible mount
- CHA HYBRID-MINI
- Selected Chameleon return system
- Compatible choked coax and tuner
- Approved guying and analyzer
CRY-03 HYBRID-MICRO
- CHA SS17 or SS25 and compatible mount
- CHA HYBRID-MICRO
- Light or mission-selected Chameleon return system
- Compatible choked coax and tuner
- Approved guying and analyzer
CRY-04 URT1 Automatic
- CHA SS25, CHA URT1 and CHA URT1-MB
- Compatible mount and URT1 ground-terminal return system
- URT1 Coupler Unit, approved uninterrupted coax/control path and specified DC supply
- Approved guying and analyzer
CRY-05A SS17 + M-COIL
- CHA SS17 and CHA M-COIL
- CHA Basic Vertical/direct-feed base and compatible mount
- Controlled 40 m radial system
- Compatible coax, approved guying and analyzer
CRY-05B SS25 + M25-COIL
- CHA SS25 and CHA M25-COIL
- CHA Basic Vertical/direct-feed base and compatible mount
- Controlled 40 m radial system
- Compatible coax, approved guying and analyzer
The lowest current power and duty-cycle rating among all installed components governs the completed system. Current manuals override workshop summaries.
Band Strategy
| Band | Best starting path | Reason |
|---|---|---|
| 80 m | Experimental URT1 or passive/tuner study | SS25-class radiator is severely short; no efficiency promise |
| 40 m | SS17 + M-COIL or SS25 + M25-COIL for dedicated performance; URT1 for agility | Radiator-matched loaded resonance versus automatic convenience |
| 30–17 m | MPAS 5:1 guide profile or URT1 | SS17 at 17 ft has documented starting SWR |
| 15–10 m | MPAS 5:1 adjusted SS17 or URT1 | SS17 at 12 ft controls match and avoids full-SS25 upper-band lobe behaviour |
| 6 m | MPAS guide SS17 at 5 ft | Documented starting geometry; full SS25 is electrically long |
Return-System Choice
- Minimum burden: one 25–35 ft MPAS wire.
- Repeatable conventional baseline: four-wire Counterpoise Kit.
- Custom educational or multiband layout: DIY Kit and Extra Wires.
- Rapid rugged deployment: FSR and FSR-A.
- Restricted footprint: Stinger Kit, pending configuration-specific validation.
Do Not Combine These Standard Paths
Do not retain a 4:1 or 5:1 transformer in the standard URT1, M-COIL or M25-COIL signal path. Cascaded matching systems can add loss, voltage/current stress and tuning ambiguity. Never substitute M25-COIL for the specified M-COIL in the standard SS17 branch, or M-COIL for M25-COIL in the standard SS25 branch. Any such experiment requires a separate research configuration ID.
Validation note: This selector states the approved engineering architecture and current evidence-backed starting priorities. It is not yet a final product-performance ranking.
