TASMA Approved · SoCal Band Plan
Simplex Frequency Guide
Simplex means radio-to-radio with no repeater in between. When repeaters are down or you just want to talk locally, these are your go-to frequencies for Southern California.
Why simplex matters: In a major earthquake, repeaters can lose power or be damaged. Simplex frequencies work with any HT, require zero infrastructure, and are the universal fallback for every ham. Always program 146.520 first.
2 Meters (144–148 MHz) — Primary Simplex Band
| Frequency | Use / Notes | Priority |
|---|---|---|
| 146.520 MHz | National 2m Calling & Emergency Frequency — the single most important simplex freq every ham must have. Universal fallback when all repeaters fail. | Must Have |
| 146.580 MHz | North American Adventure / SOTA Frequency — popular for hiking, SOTA activations, and outdoor ops throughout SoCal. | Recommended |
| 146.550 MHz | Active simplex frequency — commonly used in the LA Basin for local ragchewing and short-range contacts. | Recommended |
| 147.510 MHz | Popular simplex frequency throughout SoCal. Good second channel when 146.520 is busy. | Recommended |
| 145.570 MHz | Lake Balboa Emergency Preparedness Net — Sunday 9:00 AM. Also general simplex use. | Program |
| 145.525 MHz | TASMA approved SoCal simplex — good general use channel, less busy than 146.520. | Program |
| 145.540 MHz | TASMA approved SoCal simplex channel. | Program |
| 145.555 MHz | TASMA approved SoCal simplex channel. | Program |
| 146.445 MHz | TASMA approved SoCal simplex channel. Used occasionally for local contacts in the LA/OC area. | Program |
| 146.535 MHz | TASMA approved SoCal simplex channel. Just above the calling frequency — useful as a working channel. | Program |
| 146.565 MHz | T-hunt (foxhunt/hidden transmitter hunt) frequency in SoCal. Also general simplex. | Optional |
| 146.595 MHz | TASMA approved SoCal simplex channel. | Optional |
| 144.200 MHz | National 2m SSB Calling Frequency — weak signal, SSB mode only. Used by the Western States Weak Signal Net (Sundays 4:30 PM). | SSB/Weak Sig |
70 Centimeters (420–450 MHz) — Primary UHF Simplex
| Frequency | Use / Notes | Priority |
|---|---|---|
| 446.000 MHz | National 70cm Calling & Emergency Simplex — the 70cm equivalent of 146.520. Essential backup when 2m is congested. Every ham should have this programmed. | Must Have |
| 446.500 MHz | TASMA approved 70cm simplex for Southern California. Good secondary UHF simplex channel. | Recommended |
| 445.925 MHz | Adjacent to national calling — useful working channel after making contact on 446.000. | Program |
220 MHz / 1.25 Meters — The Hidden Gem Band
220 MHz is the least congested of the three main VHF/UHF ham bands. Excellent for simplex work — signals propagate similarly to 2m but with far less interference. If you have a tri-band HT, use it!
| Frequency | Use / Notes | Priority |
|---|---|---|
| 223.500 MHz | National 220 MHz Simplex Calling Frequency — the universal calling/emergency simplex for the 1.25m band nationwide. | Must Have |
| 223.400–223.480 MHz | Additional simplex channels on 220 MHz (15 kHz spacing in California). Less busy — good for private local contacts. | Program |
6 Meters (50–54 MHz) — "The Magic Band"
| Frequency | Use / Notes |
|---|---|
| 52.525 MHz | National 6m FM Simplex Calling Frequency — during E-skip openings this frequency lights up. SoCal ops monitor this regularly during summer sporadic-E season. |
| 50.125 MHz | National 6m SSB Calling Frequency — weak signal DX ops. During openings you can work stations across the country from SoCal. |
| 52.540 MHz | Secondary 6m FM simplex — used as a working channel after making contact on 52.525. |
📻 Simplex Best Practices for SoCal Hams
- Listen before transmitting. In the LA Basin especially, 146.520 can have ongoing QSOs you can only hear one side of due to terrain. Always listen for 10–15 seconds first.
- Keep 146.520 for calling only. Make contact, then move to a working frequency like 146.550 or 146.535 for longer QSOs.
- Program simplex AND repeaters. Alternate between simplex and your local repeater channels so you can quickly switch based on conditions.
- Simplex range varies by terrain. In flat areas like the Coachella Valley or OC, HT-to-HT simplex can reach 10+ miles. In hilly LA, it might be 1–2 miles. A mobile antenna dramatically improves range.
- SOTA & hiking. Use 146.580 (adventure frequency) for summit activations. Announce your freq on 146.520 first, then move.
Reference