EFHW and transformers

[Daniel Wee]

A comparison between the 49:1 transformers wound on FT240-43 (x1) and FT240-52 (x3).

EFHW4010-FT240-43.png (27.1 KiB) Viewed 2685 times

EFHW4010-FT240-52-auto.png (27.11 KiB) Viewed 2685 times

[Daniel Wee]

EFHW8010-FT240-52-auto.png (26.54 KiB) Viewed 2682 times

[Daniel Wee]

More tests with the 8010 with various configurations.

EFHW8010-FT240-52-auto2.png (39.97 KiB) Viewed 2674 times

EFHW8010-FT240-52-auto2-coil.png (39.39 KiB) Viewed 2674 times

EFHW8010-FT240-52-auto2-noground.png (39.31 KiB) Viewed 2674 times

EFHW8010-FT240-52-auto2-noground-elevated1.png (42.18 KiB) Viewed 2674 times

EFHW8010-FT240-52-auto2-grounded-elevated1.png (37.59 KiB) Viewed 2674 times

EFHW8010-FT240-52-noground-elevated1.png (33.71 KiB) Viewed 2674 times

EFHW8010-FT240-52-noground-choke-elevated1.png (33.44 KiB) Viewed 2674 times

EFHW8010-FT240-52B-grounded-choke.png (35.89 KiB) Viewed 2672 times

EFHW8010-FT240-52B-grounded-choke78-7.png (36.51 KiB) Viewed 2672 times

EFHW8010-FT240-52B-grounded-choke78-10-lengthened.png (35.65 KiB) Viewed 2672 times

EFHW8010-FT240-52B-noground-choke78-10-lengthened.png (32.39 KiB) Viewed 2672 times

[Daniel Wee]

Comparing a 2x FT240-43, 3x FT-240-52 and 3x FT240-52 auto SWR into a 2450ohm resistor.

[Daniel Wee]

Code: Select all

import math

#material52 = {"Al":325, "ui":250, "B":4200, "H":10, "Br":2900, "Hc":0.6, "Tc":250, "r":10e9, "u1":305, "u2":73.8}	# Al = 325
material52 = {"Al":325, "ui":250, "B":4200, "H":10, "Br":2900, "Hc":0.6, "Tc":250, "r":10e9, "u1":305, "u2":73.8}	# Al = 325
material43 = {"Al":1075, "ui":800, "B":2900, "H":10, "Br":1300, "Hc":0.45, "Tc":130, "r":10e5, "u1":140, "u2":180}	# Al = 1075
ft240 = { "Ae":1.58, "SIA":9.2, "Ie":14.5, "Ve":22.8, "radius":2.41375, "OD":6.1, "ID":3.55, "Ht":1.27}

# when stacking cores, Ae is multiplied, Ie remains constant
# leakage adjustment is based on ratio of window area to core area (Ae)
# the Al of n stacked sets are slightly less than n times the Al of a single set

Zin = 50
core = material52
stack = 1
turns = 2
Gin = 1/Zin
f = 7000000

L = (core['Al'] * 3 * turns * turns)/1000
pi = math.pi

Zt = 2 * pi * (turns**2) * (stack * core['Al']) / core['ui'] * (f / 1000000000)
X = Zt * core['u1']
R = Zt * core['u2']

G = R / (R*R + X*X)
B = -X / (R*R + X*X)

efficiency = 1-G/Gin

print(L)
print(R, X)
print(G, B)
print(efficiency*100, "%")

[Daniel Wee]

https://squashpractice.com/2021/06/23/p ... qKhRQgNFa8

https://squashpractice.com/2021/07/20/e ... d-antenna/

https://f5npv.wordpress.com/endfed-cmc/ ... Oq7FRx8PhU

https://f5npv.wordpress.com/remote-automatic-atu/

http://pa0rob.vandenhoff.info/article/u ... I3_MsV75FA

https://www.ar15.com/forums/Outdoors/DI ... 54/?page=1