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this is 144MHz 2.0 not 10 or 6m..

on July 04, 2018

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it looks more like 50 or 28 MHz

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2011-01-22 DIAMOND X30 2m 70cm 1m30 Colinear inside

Having relative poor signals on the local 70cm / 2m channels using this Diamond collinear 70/2 combi antenna at a height of 25m. I needed to investigate what could be wrong.
Measuring the cable only 3W is left for the antenna of the 10W 435MHz output from a IC451E
The cable is 30m type H100 Z50 10mm outside diameter it is semi air-spaced but has an impossible 4mm² solid CU inner conductor not much air left. I preferred the H43 Z75 cable having lower loss and mechanical better ratio in conductor size but it is no longer selling i think. This H43
3W should be enough for a comfortable noise free FM signal. But only 27km away at PA0A the signal is weak too weak something must be wrong? I made a simple reference dipole of 2x17cm CU wire.
With this dipole the signals where totally worse. So the Diamond does work?
I got curious to look inside. Maybe moisture penetration degraded the antenna.
This antenna is rainwater close in its normal vertical mounting position. But take care if your mast can b…

SPF5189z Low noise preamp 23cm

14-4-2018 updated

Above the low noise preamp 50 - 4GHz ebay 6€

Tested 2 small porto antennas
1 Baofeng UV antenna left 2nd best signal on PI2NOS
2 eBay DIAMONDSRH805S wide band 144/432/1200 it works for its size as expected
3 piece of wire : best signal in the setup...

Unit under test at workbench.
It was stable 50mA at 5V few days, but sudden the current went up to 100mA
And i could no longer adjust it with the negative bias Voltage.
The - Voltage went to zero and the SPF input port became low Z.
This SPF5189z was broken no oscillations, no input overload just it broke while i was receiving the PI2NOS 430.125 using a small antenna at the workbench.

The specs of SPF5189z say it has an internal circuit regulating the bias current.
Replaced . again with an other of the 5 spare SPF i have.
The new one again could be adjusted at 50mA 5V
The current raises to 150mA when removing the negative gate voltage.
Where is that internal bias circuit ?
I suspect eBay …

Japan 160m FT8 , VP6D at topband

In Japan digimode is allowed 1907.5 to 1912.5 kHz only FUNK FA 11/18 1087
( posible in future i am thinking of writing in German language since the Brexit why should we use Englisch ?)
JA TX USB dial 1909kHz or 1907kHz rx dial 1840kHz
EU send 1840kHz RX dial 1907 or 1909kHz where ever signals are seen.

Tonight i tried with succes for the first time with several JA stations 2-way FT8 heard HL HL3GOB dial 1907
must say it is some time ago i have seen JA in CW at 160m
JA CW is only in the JA -window 1810 to 1825kHz and that part is mostly occupied for us
In contest the only chance is calling S&P normaly and only the big guns can be worked
But in FT8 it is easy 100W!

i just set my K3 VFO A to dial 1907kHz mode DATA A
and VFO B to the usual 1840kHz

WSJT-x setup radio split operation must be none

but the K3 must be set to split TX 1840 rx 1907 kHz thats all

btw this morning VP6D was on topband weak but some QSB 1826.5 up
many EU heard calling i had to wait a go…

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