70MHz filters - Revision history

M0YDH: RBP-75

2021-04-17T17:22:24Z

RBP-75

M0YDH: BPF

2020-01-15T18:27:57Z

BPF

M0YDH: LPF filter pics

2020-01-13T18:43:39Z

LPF filter pics

M0YDH at 18:36, 13 January 2020

2020-01-13T18:36:30Z

M0YDH at 18:32, 16 November 2019

2019-11-16T18:32:46Z

M0YDH: Further 4m filters

2019-11-16T18:29:43Z

Further 4m filters

M0YDH: 4m filter page

2017-09-14T18:58:40Z

4m filter page

New page

QRP-Labs sell a Low Pass Filter kit for 4m that may be suitable for 71MHz duty with the Portsdown TX.[https://www.qrp-labs.com/lpfkit.html qrp-labs.com lpf kit ]
[[File:20170914 QRP Labs 4m and 2m LPF.jpg|300px|Low pass filter kits from QRP-Labs built by M0YDH for Portsdown TX use. 4m on left and 2m on right ]]

← Older revision		Revision as of 17:22, 17 April 2021
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	Mini-kits sell a [https://www.minikits.com.au/electronic-kits/filter-kits/vhf-lowpass-filters/LPF7-75M low pass filter kit] described as a 75MHz 7th order Chebychev Low Pass filter.		Mini-kits sell a [https://www.minikits.com.au/electronic-kits/filter-kits/vhf-lowpass-filters/LPF7-75M low pass filter kit] described as a 75MHz 7th order Chebychev Low Pass filter.

−	Band pass filters may present a problem. The [https://www.qrp-labs.com/bpfkit.html QRP-Labs 12m or 10m Band pass filter kits] may be a valid point for starting on experimentation for your receiver application. The [[71_MHz\|upconverter shown on this Wiki]] contains good filtering for receive already. [https://www.antennas-amplifiers.com/4m-70mhz-bandpass-filter-receiving Antennas-amplifiers off a bandpass filter covering 70-70.5MHz] with published characteristic curves. [https://pa3csg.nl/?page_id=62 PA3CSG] has a home built band pass filter which will tune to cover 70.5 -71.5MHz.	+	Band pass filters may present a problem. The [https://www.qrp-labs.com/bpfkit.html QRP-Labs 12m or 10m Band pass filter kits] may be a valid point for starting on experimentation for your receiver application. The [[71_MHz\|upconverter shown on this Wiki]] contains good filtering for receive already. [https://www.antennas-amplifiers.com/4m-70mhz-bandpass-filter-receiving Antennas-amplifiers off a bandpass filter covering 70-70.5MHz] with published characteristic curves. [https://pa3csg.nl/?page_id=62 PA3CSG] has a home built band pass filter which will tune to cover 70.5 -71.5MHz. 2021 update:- Mini-Circuits make an excellent low power Bandpass filter - the RBP-75+ which passes 50-72MHz signals and is for mounting on a PCB. Very low insertion loss. About £16 each or try your luck with an application to their EZ Samples programme.

← Older revision		Revision as of 18:27, 15 January 2020
Line 13:		Line 13:
	Mini-kits sell a [https://www.minikits.com.au/electronic-kits/filter-kits/vhf-lowpass-filters/LPF7-75M low pass filter kit] described as a 75MHz 7th order Chebychev Low Pass filter.		Mini-kits sell a [https://www.minikits.com.au/electronic-kits/filter-kits/vhf-lowpass-filters/LPF7-75M low pass filter kit] described as a 75MHz 7th order Chebychev Low Pass filter.

−	Band pass filters may present a problem. The [https://www.qrp-labs.com/bpfkit.html QRP-Labs 12m or 10m Band pass filter kits] may be a valid point for starting on experimentation for your receiver application.	+	Band pass filters may present a problem. The [https://www.qrp-labs.com/bpfkit.html QRP-Labs 12m or 10m Band pass filter kits] may be a valid point for starting on experimentation for your receiver application. The [[71_MHz\|upconverter shown on this Wiki]] contains good filtering for receive already. [https://www.antennas-amplifiers.com/4m-70mhz-bandpass-filter-receiving Antennas-amplifiers off a bandpass filter covering 70-70.5MHz] with published characteristic curves. [https://pa3csg.nl/?page_id=62 PA3CSG] has a home built band pass filter which will tune to cover 70.5 -71.5MHz.

← Older revision		Revision as of 18:43, 13 January 2020
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	In CQ-TV 260 Charles G4GUO published a low pass filter using ATC capacitors to go in a die cast box.		In CQ-TV 260 Charles G4GUO published a low pass filter using ATC capacitors to go in a die cast box.

		+	[[File:4m_LPF.jpg\|400px\|G4GUO filter built by David M0YDH]]
		+	[[File:4m_LPF_trace.jpg\|400px\|Spectrum analysis trace for this filter. Ref level was -14 dBm with a 10dB PAD. So -2dBm loss.]]

@@ Line 5: / Line 5: @@
 Higher power duty filters.
 In CQ-TV 260 Charles G4GUO published a low pass filter using ATC capacitors to go in a die cast box.
 Mini-kits sell a [https://www.minikits.com.au/electronic-kits/filter-kits/vhf-lowpass-filters/LPF7-75M low pass filter kit] described as a 75MHz 7th order Chebychev Low Pass filter.
 Band pass filters may present a problem. The [https://www.qrp-labs.com/bpfkit.html QRP-Labs 12m or 10m Band pass filter kits] may be a valid point for starting on experimentation for your receiver application.

← Older revision		Revision as of 18:32, 16 November 2019
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		+	Low pass filters on 4m remove signals from e.g. the broadcast radio band beginning at 88MHz.
		+
	QRP-Labs sell a Low Pass Filter kit for 4m that may be suitable for 71MHz duty with the Portsdown TX.[https://www.qrp-labs.com/lpfkit.html qrp-labs.com lpf kit ]		QRP-Labs sell a Low Pass Filter kit for 4m that may be suitable for 71MHz duty with the Portsdown TX.[https://www.qrp-labs.com/lpfkit.html qrp-labs.com lpf kit ]
	[[File:20170914 QRP Labs 4m and 2m LPF.jpg\|300px\|Low pass filter kits from QRP-Labs built by M0YDH for Portsdown TX use. 4m on left and 2m on right ]]		[[File:20170914 QRP Labs 4m and 2m LPF.jpg\|300px\|Low pass filter kits from QRP-Labs built by M0YDH for Portsdown TX use. 4m on left and 2m on right ]]

← Older revision		Revision as of 18:29, 16 November 2019
Line 1:		Line 1:
	QRP-Labs sell a Low Pass Filter kit for 4m that may be suitable for 71MHz duty with the Portsdown TX.[https://www.qrp-labs.com/lpfkit.html qrp-labs.com lpf kit ]		QRP-Labs sell a Low Pass Filter kit for 4m that may be suitable for 71MHz duty with the Portsdown TX.[https://www.qrp-labs.com/lpfkit.html qrp-labs.com lpf kit ]
	[[File:20170914 QRP Labs 4m and 2m LPF.jpg\|300px\|Low pass filter kits from QRP-Labs built by M0YDH for Portsdown TX use. 4m on left and 2m on right ]]		[[File:20170914 QRP Labs 4m and 2m LPF.jpg\|300px\|Low pass filter kits from QRP-Labs built by M0YDH for Portsdown TX use. 4m on left and 2m on right ]]
		+
		+	Higher power duty filters.
		+	In CQ-TV 260 Charles G4GUO published a low pass filter using ATC capacitors to go in a die cast box.
		+
		+	Mini-kits sell a [https://www.minikits.com.au/electronic-kits/filter-kits/vhf-lowpass-filters/LPF7-75M low pass filter kit] described as a 75MHz 7th order Chebychev Low Pass filter.
		+
		+	Band pass filters may present a problem. The [https://www.qrp-labs.com/bpfkit.html QRP-Labs 12m or 10m Band pass filter kits] may be a valid point for starting on experimentation for your receiver application.