51 MHz - Revision history

M0YDH: /* 51 MHz DATV Introduction */

2023-02-24T18:33:32Z

51 MHz DATV Introduction

M0YDH at 18:31, 24 February 2023

2023-02-24T18:31:48Z

M0YDH: low pass filter

2023-02-24T18:28:50Z

low pass filter

M0YDH: Initial details

2023-02-24T18:19:29Z

Initial details

New page

51 MHz DATV
from [https://forum.batc.org.uk/viewtopic.php?f=15&t=7847 50 MHz - a reminder - Forum post ]

The bandplan recommends 51.7 MHz. Probably best to start with 333 kHz DVB-T, QPSK, Guard 1/32, FEC 2/3.

For receive, you can tune there directly with a Knucker tuner and a Portsdown or Ryde. I would suggest a band-pass filter and a preamp (in that order).

For transmit, you can use a Portsdown 4 with LimeSDR, which will give you +1 dBm on 51.7 Mhz with a Lime Gain of 92. Or you can use a Portsdown 4 with a Pluto, which will give you -10 dBm at 0 Pluto Power (the maximum).

Dave, G8GKQ

Receive upconverter detailed on [[71_MHz|71_MHz Wiki page]] will also make a 451.7 MHz signal if DVB-S or S2 is being fed into a Minitiouner.

The Mini-Circuits RBP-75 band pass filter will pass 51.7MHz. Other low power filters are to be found on the QRP-Labs shop pages for under £5 each

A cheap, lightweight antenna for your initial tests is [https://sites.google.com/site/gw7aav2/50mhzdeltaloop Steve GW&AAV's delta loop] Also a combined pair of these antennas are shown on his 4m page.

@@ Line 15: / Line 15: @@
 The Mini-Circuits RBP-75 band pass filter will pass 51.7MHz. Other low power filters are to be found on the QRP-Labs shop pages for under £5 each
-In the [[70MHz_filters|70MHz Filters section of this Wiki]] G4GUO's low pass filter from CQ-TV-260 intended for 71MHz duty will do also well for 51.7MHz.
+In the [[70MHz_filters|70MHz Filters section of this Wiki]] G4GUO's low pass filter from CQ-TV-260 intended for 71MHz duty will do also well for 51.7MHz. Note flat top response 50 Hz [spike on left of spectrum] to 75 MHz
 A cheap, lightweight antenna for your initial tests is [https://sites.google.com/site/gw7aav2/50mhzdeltaloop Steve GW&AAV's delta loop] Also a combined pair of these antennas are shown on his 4m page.

← Older revision		Revision as of 18:31, 24 February 2023
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−	51 MHz DATV	+	==51 MHz DATV Introduction==
		+
	from [https://forum.batc.org.uk/viewtopic.php?f=15&t=7847 50 MHz - a reminder - Forum post ]		from [https://forum.batc.org.uk/viewtopic.php?f=15&t=7847 50 MHz - a reminder - Forum post ]

← Older revision		Revision as of 18:28, 24 February 2023
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	The Mini-Circuits RBP-75 band pass filter will pass 51.7MHz. Other low power filters are to be found on the QRP-Labs shop pages for under £5 each		The Mini-Circuits RBP-75 band pass filter will pass 51.7MHz. Other low power filters are to be found on the QRP-Labs shop pages for under £5 each
		+
		+	In the [[70MHz_filters\|70MHz Filters section of this Wiki]] G4GUO's low pass filter from CQ-TV-260 intended for 71MHz duty will do also well for 51.7MHz.

	A cheap, lightweight antenna for your initial tests is [https://sites.google.com/site/gw7aav2/50mhzdeltaloop Steve GW&AAV's delta loop] Also a combined pair of these antennas are shown on his 4m page.		A cheap, lightweight antenna for your initial tests is [https://sites.google.com/site/gw7aav2/50mhzdeltaloop Steve GW&AAV's delta loop] Also a combined pair of these antennas are shown on his 4m page.