Transverter Offset Guide

This guide explains how to configure and use the Transverter Offset feature in Cloudlog Aurora to correctly log contacts made through transverters.

What is a Transverter?

A transverter is a device that converts signals from one amateur radio band to another. It allows you to use an HF or VHF radio to operate on higher frequency bands like:

• 6 meters (50 MHz) using a 28 MHz IF
• 2 meters (144 MHz) using a 28 MHz IF
• 70cm (432 MHz) using a 144 MHz IF
• 23cm (1296 MHz) using a 144 MHz IF
• Higher microwave bands (2.3 GHz, 3.4 GHz, 5.7 GHz, 10 GHz, etc.)

Key Concept

Your radio displays the Intermediate Frequency (IF), but you're actually transmitting on the output frequency of the transverter.

Why Use Transverter Offset?

The Problem

When operating through a transverter, there's a critical frequency mismatch:

• Your radio shows: 144.100 MHz (the IF frequency)
• You're actually transmitting on: 1296.100 MHz (23cm)
• Without transverter offset: Cloudlog Aurora logs 144.100 MHz ❌
• With transverter offset: Cloudlog Aurora logs 1296.100 MHz ✅

The Solution

The Transverter Offset feature automatically:

1. Corrects frequency logging - Sends the actual operating frequency to Cloudlog
2. Enables remote control - Accepts frequency commands from Cloudlog for the actual band
3. Updates the UI - Displays the actual frequency you're operating on
4. Maintains compatibility - FLDigi still receives the IF frequency if enabled

How It Works

The transverter offset is applied in three key areas:

1. Frequency Logging (Radio → Cloudlog)

Radio displays: 144.100 MHz (IF)
+ Offset:       +1152 MHz
= Logged:       1296.100 MHz (actual frequency sent to Cloudlog)

2. Remote Control (Cloudlog → Radio)

Cloudlog command: Set to 1296.150 MHz
- Offset:         -1152 MHz
= Radio receives: 144.150 MHz (IF frequency sent to radio)

3. User Interface Display

The main window radio list shows the actual operating frequency, making it clear what band you're really on.

Configuration

Step 1: Open Radio Settings

1. Launch Cloudlog Aurora
2. Go to Radio → Radio Settings from the menu
3. The Radio Configuration window will open

Step 2: Configure Your Radio

Fill in the standard radio information:

Setting	Description
Radio Name	A unique identifier for this radio configuration in Aurora
Hamlib Radio ID	Your radio's model number
COM Port	The port your radio is connected to
Baud Rate	Your radio's CAT baud rate

Step 3: Enable Transverter Offset

1. Check the "Enable Transverter" checkbox
2. Enter the Offset (Hz) value
   • This will be enabled once you check the box
   • Enter the offset in Hz (not MHz)
   • Can be positive or negative

Important

Always enter the offset value in Hertz (Hz), not MHz. For example, enter 1152000000 for a 1152 MHz offset.

Step 4: Save Configuration

1. Click Save Radio (or Update Radio if editing)
2. The radio will appear in the list
3. Cloudlog Aurora automatically refreshes the frequency to Cloudlog
4. Close the Radio Settings window

Editing Existing Radios

You can also right-click on any existing radio in the Radio Settings list and select Edit to modify its configuration, including transverter settings.

Automatic Refresh

When you save or update a radio's transverter settings, Cloudlog Aurora automatically forces an immediate frequency update to Cloudlog. You don't need to change your radio's frequency or restart the application.

Calculating Your Offset

The offset is the difference between the actual operating frequency and the IF frequency your radio displays.

Formula

Offset (Hz) = Output Frequency - IF Frequency

Common Transverter Configurations

Band	Output	IF	Calculation	Offset (Hz)
6m	50 MHz	28 MHz	50 - 28 = 22 MHz	22000000
70cm	432 MHz	144 MHz	432 - 144 = 288 MHz	288000000
23cm	1296 MHz	144 MHz	1296 - 144 = 1152 MHz	1152000000
13cm	2320 MHz	144 MHz	2320 - 144 = 2176 MHz	2176000000
3cm	10368 MHz	144 MHz	10368 - 144 = 10224 MHz	10224000000

Negative Offsets (Down-converters)

If you're using a down-converter (converting a higher frequency to a lower frequency), use a negative offset:

Application	Output	IF	Calculation	Offset (Hz)
10m via 2m	28 MHz	145 MHz	28 - 145 = -117 MHz	-117000000
40m via 70cm	7 MHz	432 MHz	7 - 432 = -425 MHz	-425000000

How Down-converters Work

Example: 10m operation via 2m radio

• Radio displays: 145.000 MHz (the high IF)
• Transverter outputs: 28.000 MHz (the actual HF frequency)
• Aurora calculates: 145.000 + (-117.000) = 28.000 MHz
• Cloudlog logs: 28.000 MHz ✅

Examples

Example 1: Standard 23cm Transverter Setup

Equipment:

• Icom IC-7300 on 2m
• 23cm transverter (144 MHz → 1296 MHz)

Configuration:

Setting	Value
Radio Name	Main Station
Hamlib Radio ID	3073
COM Port	COM3
Baud Rate	19200
Enable Transverter	✅ (checked)
Offset (Hz)	1152000000

Operation Results:

• Radio displays: 144.100 MHz
• UI shows: 1296100000 Hz
• Cloudlog logs: 1296.100 MHz ✅

Remote Control Example:

• Cloudlog sends: "Set to 1296.200 MHz"
• Aurora converts: 1296.200 - 1152 = 144.200 MHz
• Radio tunes to: 144.200 MHz
• Actual frequency: 1296.200 MHz ✅

Example 2: 6m Transverter for Portable Operations

Equipment:

• Yaesu FT-991A on 10m
• 6m transverter (28 MHz → 50 MHz)

Configuration:

Setting	Value
Radio Name	Portable 6m
Hamlib Radio ID	1035
COM Port	COM5
Baud Rate	38400
Enable Transverter	✅ (checked)
Offset (Hz)	22000000

Operation Results:

• Radio displays: 28.100 MHz
• UI shows: 50100000 Hz
• Cloudlog logs: 50.100 MHz ✅

Example 3: Down-Converter for 10m Operation

Equipment:

• Radio on 2m (145 MHz)
• Down-converter/transverter (145 MHz → 28 MHz)
• Allows 10m operation using a 2m radio

Configuration:

Setting	Value
Radio Name	Mobile 10m
Hamlib Radio ID	3073
COM Port	COM3
Baud Rate	19200
Enable Transverter	✅ (checked)
Offset (Hz)	-117000000

Operation Results:

• Radio displays: 145.000 MHz (2m IF)
• UI shows: 28000000 Hz (10m)
• Cloudlog logs: 28.000 MHz ✅

Remote Control Example:

• Cloudlog sends: "Set to 28.400 MHz"
• Aurora converts: 28.400 - (-117.000) = 145.400 MHz
• Radio tunes to: 145.400 MHz
• Actual output: 28.400 MHz ✅

Use Cases for Down-converters

This configuration is useful for:

• Mobile operations where you have a dual-band 2m/70cm radio
• Using a 10m down-converter for HF operation
• Emergency HF access with VHF/UHF equipment

Example 4: Multi-Band Microwave Station

Equipment:

• Elecraft K3 on 2m
• Multiple transverters: 23cm, 13cm, 6cm, 3cm

Solution: Create separate radio configurations for each band:

Configuration 1: 23cm

Setting	Value
Radio Name	Shack - 23cm
Hamlib Radio ID	2029
COM Port	COM3
Baud Rate	38400
Enable Transverter	✅ (checked)
Offset (Hz)	1152000000

Configuration 2: 13cm

Setting	Value
Radio Name	Shack - 13cm
Hamlib Radio ID	2029
COM Port	COM3
Baud Rate	38400
Enable Transverter	✅ (checked)
Offset (Hz)	2176000000

Configuration 3: 3cm

Setting	Value
Radio Name	Shack - 3cm
Hamlib Radio ID	2029
COM Port	COM3
Baud Rate	38400
Enable Transverter	✅ (checked)
Offset (Hz)	10224000000

Multi-Band Usage

Select the appropriate "radio" configuration in Cloudlog Aurora based on which transverter you're currently using.

Testing Your Configuration

1. Verify Frequency Logging

1. Start Cloudlog Aurora with your transverter-enabled radio configuration
2. Tune your radio to a known IF frequency (e.g., 144.100 MHz)
3. Check the main window - Should display the actual frequency (e.g., 1296.100 MHz)
4. Log into Cloudlog web interface
5. Check the station's radio frequency - Should show the actual band frequency

Expected Results

• Radio: 144.100 MHz
• Aurora display: 1296100000 Hz
• Cloudlog display: 1296.100 MHz ✅

2. Test Remote Control

1. Log into Cloudlog web interface
2. Navigate to your station profile
3. Use radio control to set a frequency on the actual band
   • Example: Set to 1296.200 MHz
4. Check your radio - Should tune to the IF frequency
   • Example: Should show 144.200 MHz

Expected Results

• Command: 1296.200 MHz
• Radio tunes to: 144.200 MHz ✅
• Actual output: 1296.200 MHz ✅

3. Verify Console Output

Check the Cloudlog Aurora console for confirmation messages:

Frequency Logging:

Radio Main Station - Transverter offset applied: 144100000 Hz -> 1296100000 Hz (+1152.000 MHz)

Remote Commands:

[RadioCommands] Transverter enabled - converting actual freq 1296200000 Hz to radio/IF freq 144200000 Hz (offset: +1152.000 MHz)
[RadioCommands] SET_FREQ result: SUCCESS

Troubleshooting

Problem: Cloudlog not updating after changing offset

Symptoms

• You changed the transverter offset in Radio Settings
• Aurora UI shows the new frequency correctly
• Cloudlog still shows the old frequency

Solutions:

1. Wait for the next poll cycle - Updates happen within your configured poll time (typically 500ms-1000ms)
2. Check console output - Look for messages like:

   [RadioSettings] Triggered frequency refresh for edited radio: My Radio
   [RefreshRadio] Cleared cached frequency for radio: My Radio
   Radio My Radio - Transverter offset applied: 145000000 Hz -> 28000000 Hz (-117.000 MHz)
3. Verify polling is enabled - Check that the radio's checkbox is checked in the main window
4. Tune the radio slightly - Moving the frequency by even 1 kHz will trigger an immediate update

Automatic Update

As of the latest version, Cloudlog Aurora automatically clears the frequency cache and forces an update when you change transverter settings. If this doesn't work, there may be a configuration issue.

Problem: Wrong frequency logged in Cloudlog

Symptoms

• Radio shows 144.100 MHz
• Cloudlog logs 144.100 MHz instead of 1296.100 MHz

Solutions:

1. Verify "Enable Transverter" is checked in Radio Settings
2. Verify the offset value is correct (e.g., 1152000000 for 23cm)
3. Check console output for "Transverter offset applied" messages
4. Restart Cloudlog Aurora after making changes

Problem: Radio won't respond to remote commands

Symptoms

• Cloudlog sends "Set to 1296.200 MHz"
• Radio doesn't change frequency or tunes to wrong frequency

Solutions:

1. Verify the offset calculation is correct
2. Check console output for frequency conversion messages
3. Test with transverter disabled to verify basic radio control works
4. Ensure the radio configuration is properly saved and selected in Aurora

Problem: UI shows wrong frequency

Symptoms

• Radio shows 144.100 MHz
• Aurora UI shows 144100000 Hz instead of 1296100000 Hz

Solutions:

1. Close and reopen Cloudlog Aurora
2. Verify transverter settings were saved (check radiosettings.json)
3. Check that you're looking at the correct radio in the list

Problem: FLDigi receives wrong frequency

This is Actually Correct!

This is not a problem - it's the intended behavior.

Expected Behavior:

• Radio: 144.100 MHz
• Aurora UI: 1296.100 MHz
• Cloudlog: 1296.100 MHz
• FLDigi: 144.100 MHz ✅

FLDigi should receive the IF frequency (what the radio displays), not the actual frequency. This is intentional because FLDigi needs to sync with your radio's displayed frequency for modes like WSPR, FT8, etc.

Problem: Negative frequencies after remote command

Symptoms

• Cloudlog sends command for a frequency lower than the offset
• Results in calculation error

Example:

Offset: +1152 MHz
Command: 1000 MHz (below 1152 MHz)
Calculation: 1000 - 1152 = -152 MHz ❌

User Error

This is a user error. When using transverters, only send frequencies within the valid output range:

• For 23cm with 144 MHz IF: Use frequencies ≥ 1296 MHz
• For 13cm with 144 MHz IF: Use frequencies ≥ 2320 MHz

Problem: Down-converter configuration not working

If you're using a down-converter (e.g., receiving 1296 MHz on a 2m radio):

1. Verify the offset is set as a negative value
2. Check that the output frequency is lower than the IF frequency

Example Configuration:

Output:  1296 MHz
IF:      144 MHz
Offset:  1296 - 144 = 1152 MHz (enter as negative offset)
Enter:   -1152000000 Hz

Advanced Use Cases

Multiple Radios with Different Transverters

You can configure multiple radios, each with different transverter settings:

Configuration	Band	Offset (Hz)
Main - Direct	All HF/VHF	0 (no transverter)
Main - 23cm	1296 MHz	+1152000000
Main - 13cm	2320 MHz	+2176000000

Use Case

Quickly switch between bands by selecting the appropriate radio configuration in Cloudlog Aurora, even though they're all using the same physical radio.

Transverters with Non-Standard IF Frequencies

Some transverters use non-standard IF frequencies:

Band	Output	IF	Calculation	Offset (Hz)
23cm	1296 MHz	28 MHz	1296 - 28 = 1268 MHz	1268000000
3cm	10368 MHz	432 MHz	10368 - 432 = 9936 MHz	9936000000

Down-Converters and Receive-Only Setups

Down-converters are transverters that convert a higher IF frequency to a lower output frequency. These are less common than traditional transverters but are useful for specific applications.

Common Down-Converter Use Cases

1. HF Operation with VHF Radios

Use a 2m radio to operate on 10m:

Equipment: 2m radio + 10m down-converter
Radio displays: 145.000 MHz
Actual output:  28.000 MHz
Offset:         28 - 145 = -117 MHz
Enter:          -117000000 Hz

How it works:

• Your 2m radio tunes to 145.000 MHz
• Down-converter outputs 28.000 MHz
• Aurora logs the actual 10m frequency
• Perfect for mobile HF operation with VHF equipment

2. Receive Converters

Receiving higher frequencies on a lower-band radio:

Example: Receiving 1296 MHz on a 2m radio
Input frequency: 1296 MHz (what you're receiving)
Radio displays:  144 MHz (the IF)
Offset:          1296 - 144 = 1152 MHz
Enter:           1152000000 Hz

Note: Even though you're not transmitting, the offset allows proper frequency logging.

3. Specialized Applications

Some operators use down-converters for:

• Emergency communications - HF access with VHF-only equipment
• Contest operations - Using high-performance VHF radios on HF
• Satellite operations - Complex IF arrangements
• Experimental setups - Testing and development

Down-Converter Configuration Example

Full Configuration:

Setting	Value
Radio Name	Mobile HF via 2m
Hamlib Radio ID	3073
COM Port	COM3
Baud Rate	19200
Enable Transverter	✅ (checked)
Offset (Hz)	-117000000

Results:

• Radio at 145.100 MHz → Logs as 28.100 MHz
• Radio at 145.500 MHz → Logs as 28.500 MHz
• Cloudlog command "28.400 MHz" → Radio tunes to 145.400 MHz

Important Notes for Down-Converters

1. Always use negative offsets - Output < IF = negative number
2. Test thoroughly - Verify frequency calculations before operating
3. Watch for tuning limits - Ensure your radio can tune the required IF range
4. Check power levels - Some converters have gain/attenuation

Quick Reference

Common Offsets (in Hz)

Band	IF Frequency	Output Frequency	Offset (Hz)	Type
Standard Transverters (Positive Offsets)
6m	28 MHz	50 MHz	22000000	Up-converter
2m	28 MHz	144 MHz	116000000	Up-converter
70cm	144 MHz	432 MHz	288000000	Up-converter
23cm	144 MHz	1296 MHz	1152000000	Up-converter
13cm	144 MHz	2320 MHz	2176000000	Up-converter
9cm	144 MHz	3456 MHz	3312000000	Up-converter
6cm	144 MHz	5760 MHz	5616000000	Up-converter
3cm	144 MHz	10368 MHz	10224000000	Up-converter
1.2cm	144 MHz	24192 MHz	24048000000	Up-converter
Down-Converters (Negative Offsets)
10m	145 MHz	28 MHz	-117000000	Down-converter
10m	432 MHz	28 MHz	-404000000	Down-converter
40m	432 MHz	7 MHz	-425000000	Down-converter
80m	432 MHz	3.5 MHz	-428500000	Down-converter

Offset Calculation Cheat Sheet

Positive Offset (Most Common)

Output Frequency > IF Frequency
Offset = Output - IF
Example: 1296 MHz - 144 MHz = +1152 MHz

Negative Offset (Down-converters)

Output Frequency < IF Frequency
Offset = Output - IF (will be negative)
Example: 28 MHz - 145 MHz = -117 MHz

Tips and Best Practices

Radio Naming Convention

Use descriptive names that indicate the band:

• ✅ Good: "Main - 23cm", "Portable - 6m", "Shack - 13cm"
• ❌ Avoid: "Radio 1", "Transverter", "Test"

Key Recommendations

1. Use Descriptive Radio Names - Give each radio configuration a unique, descriptive name that helps you identify the setup (e.g., "Main - 23cm", "Portable - 6m").

2. Document Your Offsets - Keep a record of your transverter specifications and calculated offsets for reference.

3. Test Before Operating - Always test frequency logging and remote control before making contacts to ensure everything is working correctly.

4. Monitor Console Output - Keep an eye on the console output to verify transverter offset calculations are being applied correctly.

5. One Configuration Per Transverter - If you switch between multiple transverters on the same radio, create separate radio configurations for each, rather than trying to change the offset on the fly.