HG5RTV SSTV Repeater

Latest received images

Operating instructions

Who may use the repeater?

Reception: Anyone may receive the repeater who has an FM receiver capable of narrowband FM (NFM) reception on 432.525 MHz, and has suitable software for SSTV decoding.

(Please do not use wide-FM (WFM) mode, as SSTV signals will be distorted and cannot be decoded properly.)

Transmission: Only individuals holding a valid amateur radio callsign may transmit into the repeater.
The SSTV software must be configured with the operator’s licensed callsign, including any required portable or location suffix (e.g. HG5XYZ or HG5XYZ/P).

Receiving the status image:
The repeater transmits a status image (beacon) every 10 minutes in Martin-2 mode.

Send an image to the repeater:
The repeater is activated by sending a 1750 Hz tone (minimum 1.5 seconds) generated from the SSTV client transmit interface.
After receiving the call tone, the repeater sends its identification in FM CW, then goes silent.
Upon hearing the CW ID, the operator should count to two and start transmitting (TX image) within 4 seconds.
Please enable the transmission of FSK ID in your SSTV software so the repeater and the website`s statistics system can correctly detect your callsign.

Where to find it?
• MMSSTV: bottom of main window → `TxID` checkbox
• QSSTV: QSSTV automatically sends an FSKID at the end of the transmission if the callsign is set in Configuration → Operator, and the CW option (Send CW at end) in the TX window is disabled. There is no separate FSKID switch; FSKID is sent automatically when these conditions are met. Please use QSSTV version 9.3 or newer.

After receiving the image, the repeater appends its own banner to the bottom of the picture and retransmits it in the same mode it was received.
Once retransmission is complete, the repeater returns to standby awaiting the next activation.

Recommended SSTV Modes for Use with the Repeater:

For optimal repeater operation and good image quality, the following SSTV modes are recommended:

Martin-1

• Resolution: 320 × 256 pixels
• Image quality: very good
• Transmission time: ~114 s

Martin-2

• Resolution: 320 × 256 pixels
• Image quality: good
• Transmission time: ~57 s

Scottie 2 (SC2-120)

• Resolution: 320 × 256 pixels
• Image quality: excellent
• Transmission time: ~120 s

For high-quality, detailed image transmission, Martin-1 or Scottie 2 (SC2-120) modes are recommended.
If a shorter transmission time is desired, Martin-2 provides a good compromise.

Please avoid using very slow modes (longer than 120 seconds) on the repeater (e.g. Scottie DX, Robot DX, and similar long-duration modes).

Recommended software for using the SSTV repeater:

• MMSTV (Windows XP – Windows 11)
• QSSTV (sw ver. 9.3-) (Linux)
• Robot36 – SSTV Image Decoder (Android, receive only)

Coverage / QTH site

Coverage map

Site photos (QTH)

Technical information

• MMSTV software, repeater mode
• Motorola GM300 UHF transceiver – TX power: 10W
• Antenna: Diamond X50N
• Frequency: 432.525 MHz FM

QTH data

• Budapest, Széchenyi Hill
• Locator: JN97LL
• Altitude: 420m ASL

Contact

Station manager:
HG5OJG Gergo

FAQ – Using the SSTV Repeater

1. What kind of content may I transmit through the repeater?

• Only material appropriate for amateur radio communication, suitable for all audiences.
• Forbidden: political, sexual, hateful, or otherwise offensive content.

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2. How should I prepare the image before transmission?

• Leave the bottom part of the image empty, as the repeater adds its own status banner there.
• Your callsign must be clearly visible, with good contrast and readable font size.
• Do not place important text where the banner will appear.

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3. What should a QSO image look like?
  The image should contain:

• the other station’s callsign,
• your own callsign (DE HG5XYZ),
• the signal report (e.g. RST: 595).

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4. What should a CQ call look like in SSTV?
  Recommended image content:
  CQ SSTV DE HG5XYZ
  Use clear, high-contrast text.

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5. Is FSKID required?
  Yes, FSKID is mandatory.
  It ensures that the repeater and the website can correctly identify the transmitting station.
  (Configuration instructions are provided in the section above.)

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6. Is a top banner required?
  Not required, but recommended. It may include:

• your QTH,
• the name and version of the SSTV software used,
• an optional callsign header.

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7. What audio level should I use?
  Too strong or too weak audio will degrade decoding quality.
  Recommendations:

• avoid distortion,
• keep signal peaks within the radio’s passband (~3 kHz),
• use a stable and consistent audio level.

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8. Why may an image appear slanted or shifted?

• QSSTV may require TX slant correction in the software.
• MMSSTV automatically corrects most drift.
• The repeater’s Auto-Slant function also helps compensate during reception.

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9. What should I do if the repeater does not start after the tone?

• Ensure the repeater is not already receiving an image (you may not always hear the other station). Wait 2–3 minutes.
• Verify that the tone is 1750 Hz and lasts at least 1.5 seconds.
• Check your transmitter’s output power level.
• If the tone audio level is too low, increase it. (Verify with a monitoring receiver.)