Topics

BC breakthrough

Trent Trent
 

I just made my first and fuckin LAST crkits 20M FT8 transceiver,i've done most of it on the TX side and as I done the RX side which it is missing the needed 27p cap all I get is fuckin BC from ABC radio here in VK7 no matter what I do

Bruce
 

Wow a little angry there.  Part of this hobby is fixing problems as they come up. A 27pf cap is a jelly bean part which can be purchased at any supply house. If you don't want to purchase one, harvest one from something else. It's a simple problem, quit your cussing and figure it out.

Adam Rong
 

Trent,

BCI is the nature of a direct conversion receiver. The crystal and the 27p cap in the front end will help reduce it, however I did receive a BCI report from Beijing where the MW broadcast station is nearby, after selling over 100 kits. An additional BCI filter inserted between antenna and the D4D will be helpful. If you can confirm MW station is the major problem, you can consider making one following this page:
http://www.calculatoredge.com/electronics/ch%20pi%20high%20pass.htm

Thanks,
Adam

在 2019年6月25日,上午11:10,Trent Trent <vk7hrs@...> 写道:

I just made my first and fuckin LAST crkits 20M FT8 transceiver,i've done most of it on the TX side and as I done the RX side which it is missing the needed 27p cap all I get is fuckin BC from ABC radio here in VK7 no matter what I do

Trent Trent
 

Where I am the nearest AM BC antenna is over 50K away so I have nothing near me onAM


On Tue, 25 Jun 2019 at 21:26, Adam Rong <rongxh@...> wrote:
Trent,

BCI is the nature of a direct conversion receiver. The crystal and the 27p cap in the front end will help reduce it, however I did receive a BCI report from Beijing where the MW broadcast station is nearby, after selling over 100 kits. An additional BCI filter inserted between antenna and the D4D will be helpful. If you can confirm MW station is the major problem, you can consider making one following this page:
http://www.calculatoredge.com/electronics/ch%20pi%20high%20pass.htm

Thanks,
Adam

在 2019年6月25日,上午11:10,Trent Trent <vk7hrs@...> 写道:

I just made my first and fuckin LAST crkits 20M FT8 transceiver,i've done most of it on the TX side and as I done the RX side which it is missing the needed 27p cap all I get is fuckin BC from ABC radio here in VK7 no matter what I do

gm0sim@...
 

I still think that a $39 kit that fits in a cigarette packet sized box as a cheap introduction to FT8 is a valid and useful product for many (OK not all but you have to accept some compromises for that price/size).

Surely that is the whole point of AMATEUR radio... self training & the ability to investigate and resolve problems yourself.

Although... who should I complain to about the state of the ionosphere at the moment... that is just not on 🙁

regards- Ian gm0sim


From: crkits@groups.io <crkits@groups.io> on behalf of Trent Trent <vk7hrs@...>
Sent: 25 June 2019 04:10
To: crkits@groups.io
Subject: [crkits] BC breakthrough
 
I just made my first and fuckin LAST crkits 20M FT8 transceiver,i've done most of it on the TX side and as I done the RX side which it is missing the needed 27p cap all I get is fuckin BC from ABC radio here in VK7 no matter what I do

Adam Rong
 

Folks,

I agree that problem solving is part of Amateur Radio, especially dealing with BCI. However, as the designer and kit provider, I should have made it clear that this is something new and people may meet problems.

Perhaps it is good idea to find the source of the interference first. I did a web search and found the following stations in Hobart, Tasmania very near you:
ABC Radio 936kHz
ABC RN 585kHz
ABC News on Radio 747kHz

Compare with an AM radio receiver and you will find out the possible source of interference. If you are not sure about the finding, perhaps you can contact ABC to know the frequency list and distance of the interference, including LW, MW and SW, so you can insert a band stop or other type of filter.

Personally I have a similar experience to identify a strong BCI and finally found the source of the noise. It is a lot of fun indeed and it is good for you as you can start to try many more kits of direction conversion type later.

I appreciate all the feedback and I think it is part of the experience of providing the kit. Let me know if you need me to ship the missing part. As I am getting 42, I start to forget something. If you need me to refund to cover the postage and cost of sourcing locally, I will be glad to do so. A happy customer is more important, always.

Thanks,
Adam

Zach Davis - AB0E
 

For the 20m kit which do you all think would be better a MW bandstop or a 20m Bandpass?

 

A simple BCI filter on the RX path would solve this issue.

 

Trent Trent
 

The better option is puttin a BPF instead of a LPF which is the better way but as I have constant headaches etc doe to pressure on my spinal cord I cant out the values and the online online calcs are useless

Bryan Corkran, VK3KEZ
 

On 27 Jun 2019, at 9:50 am, Trent Trent <vk7hrs@...> wrote:

The better option is puttin a BPF instead of a LPF which is the better way but as I have constant headaches etc doe to pressure on my spinal cord I cant out the values and the online online calcs are useless

Cues Ahero
 

trent,i have chronic cluster headache,terminal scleraderma and my kit building days are. pretty much gone due to parkinsons at the moment. i envy your current kit problem. cheers,p


On Wed, Jun 26, 2019, 4:50 PM Trent Trent <vk7hrs@...> wrote:
The better option is puttin a BPF instead of a LPF which is the better way but as I have constant headaches etc doe to pressure on my spinal cord I cant out the values and the online online calcs are useless

Cues Ahero
 

although i feel your pain :),......


On Thu, Jun 27, 2019, 1:11 PM Cues Ahero via Groups.Io <My09vstrom1=gmail.com@groups.io> wrote:
trent,i have chronic cluster headache,terminal scleraderma and my kit building days are. pretty much gone due to parkinsons at the moment. i envy your current kit problem. cheers,p

On Wed, Jun 26, 2019, 4:50 PM Trent Trent <vk7hrs@...> wrote:
The better option is puttin a BPF instead of a LPF which is the better way but as I have constant headaches etc doe to pressure on my spinal cord I cant out the values and the online online calcs are useless

david todd
 

trent, 
sounds like you solved your problem bpf.But before building one, 

why dont you put the rig in some shielding and build an inline filter before the rig?maybe install some caps to ground?

maybe .o1 uf ceramics to ground? i have built mine today and it receives  fine. took it mobiling with me   i dont have this problem.But they probably dont run the freqs yours does.
 
I physically connected a ground wire to the case of my radio and hooked it up to the nearest ground connection which at home is the 8 ft triad ground rods i have driven into the dirt for other equipment.Not only do i have an antenna ground i have an earth ground too to the case of the radio.it really reduced the noise in my receiver..

I started out with an old johnson viking tube rig with an s38b receiver. :). I ground everything including my wife from my bank account hi hi. one wire with a ring connector or fork if you dont have the ring. or rap the ground wire around the screw and tighten. see if that helps.