AF7KR HF antenna splitter v2 - EasyEDA open source hardware lab

Std edition AF7KR HF antenna splitter v2

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License: CC-BY-SA 3.0

Project source: Cloned from AF7KR HF antenna splitter

Published Time: 2021-11-03 22:45:10

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Description

Active splitter to use 1 HF antenna with multiple receivers. Includes bias T, 35MHz LPF and 1.8MHz HPF. The response in the bandpass is flat, +/-1dB. FM radio suppression is very good, 60..80dB. Observed oscillations aound 70MHz when only one output is loaded. If you see this, load the unused outputs (a short or 50 Ohm is ok). The bias T choke may saturate if the preamp current is more than 50mA. Use a bigger core of fewer turns for higher current. If you measure IP2/IP3, please let me know.

Design Drawing

schematic diagram

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BOM

BOM download Purchase Parts

ID	Name	Designator	Footprint	Quantity
1	680	C1,C4	1206	2
2	470	C2,C3	1206	2
3	1u	C5,C11,C12,C13,C14,C15,C16,C17,C18,C19,C20,C21	1206	12
4	10n	C6	1206	1
5	47	C7,C10	1206	2
6	150	C9	1206	1
7	1N4148	D1	D_DO-35_SOD27_P5.08MM_VERTICAL_KATHODEUP	1
8	LO	J1,J3	HDR-1X2/2.54	2
9	+12V	J2	HDR-1X2/2.54	1
10	470u	L1	L_T50_VERTICAL	1
11	4.3u	L2,L4	L_T50_VERTICAL	2
12	4.1u	L3	L_T50_VERTICAL	1
13	0.33u	L5,L6	L0805	2
14	RF IN	P1	CONN-SMD_KH-SMA-KE8-G	1
15	OUT1	P2,P3,P4,P5	CONN-SMD_KH-SMA-KE8-G	4
16	MMBT2222A	Q1,Q3,Q5,Q7	PG-SOT23-3_L2.9-W1.3-P1.90-LS2.4-BR	4
17	MMBT2907A	Q2,Q4,Q6,Q8	PG-SOT23-3_L2.9-W1.3-P1.90-LS2.4-BR	4
18	430	R1,R3	1206	2
19	220	R2	1206	1
20	27	R4,R6,R8,R10	1206	4
21	22	R5,R7,R9,R11	1206	4
22	XFMR	T1	BN43-2402	1