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Frequency Counter

richard kappler #24382 I am working on strengthening my kit building skills before I tackle my next Bitx40, so I have built the ?frequency counter and should have the parts for a coupla antenna analyzers tomorrow. Regarding the freq counter, it has 4 "inputs", a pair of grounds, 8-15 VDC and sig in. I have two questions: 1. Any reason I shouldn't hook the VDC in to the incoming power for the BitX?? 2. Regarding Sig In, I should connect this to the brown (center) of the antenna output? regards, Richard -- W2KAP In any given circuit, the most expensive part will always sacrifice itself to protect the fuse.
Arv Evans All Messages By This Member #24383 Richard W2KAP It is normal to connect your frequency counter to the VFO output, and to program in an IF offset.? This lets the counter tell you the operating frequency when receiving and transmitting.? Connecting the counter to the antenna port could be bad for several reasons.? (1) it would only show frequency when transmitting. and (2) the RF power available at the antenna port when transmitting could do bad things to your frequency counter. Arv? K7HKL _._ toggle quoted message Show quoted text On Sun, Apr 2, 2017 at 12:11 PM, richard kappler <richkappler@...> wrote: I am working on strengthening my kit building skills before I tackle my next Bitx40, so I have built the ?frequency counter and should have the parts for a coupla antenna analyzers tomorrow. Regarding the freq counter, it has 4 "inputs", a pair of grounds, 8-15 VDC and sig in. I have two questions: 1. Any reason I shouldn't hook the VDC in to the incoming power for the BitX?? 2. Regarding Sig In, I should connect this to the brown (center) of the antenna output? regards, Richard -- W2KAP In any given circuit, the most expensive part will always sacrifice itself to protect the fuse.
Michael Hagen All Messages By This Member #24384 What do you want to measure? It has 100 Ohm input resistance on input transistor base ( Cap Coupled).? So you need to find a signal somewhere that this low impedance won't load down? Mike, WA6ISP
richard kappler #24385 Nothing in particular, trying to learn. toggle quoted message Show quoted text On Apr 2, 2017 2:25 PM, "Michael Hagen" <motdog@...> wrote: What do you want to measure? It has 100 Ohm input resistance on input transistor base ( Cap Coupled).? So you need to find a signal somewhere that this low impedance won't load down? Mike, WA6ISP
Michael Hagen All Messages By This Member #24387 开云体育 You might put a 1K in series with the input.? Thus it would take a larger signal but load the test circuit less. Try on the gate of the IRF510?? That's a pretty good stiff signal at your transmit frequency. Try it on the SL5351 output. It is good to experiment, this radio has a lots to learn about! It is a wonderful base to experiment with.? I will use mine mostly for playing with the receiver and Arduino code. I don't have an antenna.? So it will be a long wire out the door and /or the Signal Generator! I have already made PCBs (stamp sized) for the Silicons Labs oscillator and have a Nano driving it with I2C. The examples in the Arduino Code work!? Sweeping, Fixed Freq. ect.? The library makes it magic. Mike, WA6ISP On 4/2/2017 11:27 AM, richard kappler wrote: toggle quoted message Show quoted text Nothing in particular, trying to learn. On Apr 2, 2017 2:25 PM, "Michael Hagen" <motdog@...> wrote: What do you want to measure? It has 100 Ohm input resistance on input transistor base ( Cap Coupled).? So you need to find a signal somewhere that this low impedance won't load down? Mike, WA6ISP
richard kappler #24389 And this is why I love this hobby and this list. Thanks Mike! regards, Richard? toggle quoted message Show quoted text On Apr 2, 2017 2:58 PM, "Michael Hagen" <motdog@...> wrote: You might put a 1K in series with the input.? Thus it would take a larger signal but load the test circuit less. Try on the gate of the IRF510?? That's a pretty good stiff signal at your transmit frequency. Try it on the SL5351 output. It is good to experiment, this radio has a lots to learn about! It is a wonderful base to experiment with.? I will use mine mostly for playing with the receiver and Arduino code. I don't have an antenna.? So it will be a long wire out the door and /or the Signal Generator! I have already made PCBs (stamp sized) for the Silicons Labs oscillator and have a Nano driving it with I2C. The examples in the Arduino Code work!? Sweeping, Fixed Freq. ect.? The library makes it magic. Mike, WA6ISP On 4/2/2017 11:27 AM, richard kappler wrote: Nothing in particular, trying to learn. On Apr 2, 2017 2:25 PM, "Michael Hagen" <motdog@...> wrote: What do you want to measure? It has 100 Ohm input resistance on input transistor base ( Cap Coupled).? So you need to find a signal somewhere that this low impedance won't load down? Mike, WA6ISP
DuWayne Schmidlkofer All Messages By This Member #24400 You will want to take the signal off of the VFO output, then you can program in the BFO to get the correct Frequency Display. The counter will put an awful lot of noise on the DC line on the BITX board. When I tried a similar counter, I had to feed the counter through a 10MH choke with 100Uf capacitors on each side to get the noise down to an acceptable level. -- DuWayne? KV4QB

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