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How to simplify logging?
Forum: Digital Modes
Last Post: VK5PJ
Today, 12:43 AM
» Replies: 2
» Views: 65
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7285kHz AM?
Forum: Off Topic!
Last Post: VK3RX
Yesterday, 01:16 PM
» Replies: 0
» Views: 51
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VK3XPD 23cm 65W modules
Forum: 1296MHz, Microwave & Opto
Last Post: VK2AZ
22-04-2024, 09:34 PM
» Replies: 1
» Views: 171
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Dud Headphone Jack on Yae...
Forum: Transceivers, Transmitters & Receivers
Last Post: VK2CSW
20-04-2024, 07:53 AM
» Replies: 1
» Views: 362
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23-on-23: Tuesday April 2...
Forum: 1296MHz, Microwave & Opto
Last Post: VK4CZ
19-04-2024, 01:22 PM
» Replies: 0
» Views: 342
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Audio Clipping on Sideban...
Forum: LF, HF, MF
Last Post: VK2CSW
17-04-2024, 08:27 PM
» Replies: 3
» Views: 1,160
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FTDX101D & SCU17 ?
Forum: General Discussion
Last Post: VK4TS
16-04-2024, 10:50 AM
» Replies: 1
» Views: 459
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Wiring a microphone for h...
Forum: Homebrew
Last Post: VK2CSW
15-04-2024, 07:47 PM
» Replies: 7
» Views: 2,385
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Dipole for 6m
Forum: 50MHz
Last Post: VK2CSW
15-04-2024, 07:10 PM
» Replies: 6
» Views: 1,559
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Toroid Supplier/s
Forum: Ancillary, Test Equipment, Components & Parts
Last Post: VK2CSW
11-04-2024, 06:26 PM
» Replies: 3
» Views: 1,142
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AHRDF Christmas opening hours 2018 |
Posted by: VK4ADC - 23-12-2018, 06:45 PM - Forum: General Discussion
- Replies (5)
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Well good news for all:
This Forum will be open all hours over the Christmas and New Year celebration periods.
There typically won't be any staff on daily duty as the process will be 'serve yourself' - as is normal.
Here's hoping that you have a very enjoyable Christmas and a safe and Happy New Year.
73, Doug
Admin
P.S. New members registering will have to wait for manual activation - which could be within an hour or could take two days. Keep an eye on the Forum and your email to see when it happens.
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YU1LM HF/6M BPF designs - anyone built any ? |
Posted by: VK4ADC - 13-12-2018, 03:18 PM - Forum: General Discussion
- Replies (2)
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Has anyone built and tested the YU1LM bandpass filters as per http://yu1lm.qrpradio.com/HF-6m%20BP%20YU1LM%20ver3.pdf ?
I haven't run the Ansoft Designer spice-like software on them but I have built a couple of them up (10 & 14MHz) using the values as per Table 1 to find that they don't provide the expected (/published) results. My measurement process is manual as I don't have a tracking generator but am using a microwattmeter (displays in dBm) plus a sign gen at +6dBm to validate the actual response values.
I have had to tamper with the capacitance values a bit to get (1) the pass loss low at 10 and 14; and (2) provide the desired centre frequency characteristic. Untouched, they are off-frequency and the shape of the response is far slower to fall off than in the 'BP for 10MHz' and 'BP for 14MHz' graphs in the article.
Mine are each built on a small PCB about 40mm long x 12mm wide using SMD components, the boards then plug onto a "test" baseboard so that their results could be checked.
Fortunately I have a degree of flexibility in the actual filter design as the PCB layout is two rows of a series of rectangular pads that will allow a lot of different configurations. I can experiment a bit to try to improve the outcome.
The destination of these BPFs is my Raspberry PI WSPR beacon project (Pi Zero plus small PA ~ 200mW + 4 x BPFs switched by SMD relays) and I am currently targetting good 10, 14, 18 and 50 MHz designs. I need to clean up the PI's output spectrum hence the need for the BPFs.
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CW for advanced license? |
Posted by: VK4WDM - 30-11-2018, 08:36 AM - Forum: Regulatory, Licencing & Exams
- Replies (2)
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I have been told by a person studying for their advanced license that there is an option for them to be tested in CW proficiency at 5 WPM as part of the exam. I can't find any mention of that in the exam syllabus. Is that correct?
Wayne VK4WDM
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JS8Call |
Posted by: VK4WDM - 29-11-2018, 07:35 PM - Forum: Digital Modes
- No Replies
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Anybody tried a mode called JS8CALL?
Wayne VK4WDM
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