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Re: Assembled HT-1A from USA location
John
Thank you and have a great week. John K2JHU... On Sat, Nov 2, 2019 at 6:58 PM Adam Rong <rongxh@...> wrote:
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Re: Use scope to check audio input level to D4D?
开云体育If you don’t have RF test equipment like spectrum analyzer, you can use WSJTx spectrum to make rough judgements. Transmit with D4D and receive with other rig and observe the received spectrum. The overtones in audio range will reflect the distortion.You will have to find a balance. The recommended modifications will give you good balance. Thanks, Adam 在 2019年11月3日,上午6:12,Jim WB2LHP in MI <jmarco1955@...> 写道:
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Re: Assembled HT-1A from USA location
开云体育John,I have an over time and full time job, so the shipping will be every Monday. Your rig will be shipped next Monday via EMS, and after shipment, the tracking number will be updated in PayPal. Thanks, Adam 在 2019年11月3日,上午1:56,John <johnk2jhu@...> 写道:
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Re: Use scope to check audio input level to D4D?
Jim WB2LHP in MI
I've been working on this issue also Adrian...Right now I'm testing two solutions...The first is to incorporate the KD1JV resistive divider mod...I use a 33K/1K combo to get the level I want...The other is simpler...Replace C6 with a 0.1uf cap and C5 with a 10uf electrolytic...This capacitive divider ratio should accomplish the same thing and keep the mixer from saturating...Expect your power output to be significantly?lower but with much greater spectral purity...Without the mods, the signal is about 75KHz wide!...I'll report on my testing later after I have access to the spectrum analyzer and wattmeter again...Jim? WB2LHP On Sat, Nov 2, 2019 at 5:53 PM Adrian Boyko <adrianboyko@...> wrote: Hi All. I'm curious if there's a point in the D4D circuit that would allow for an easy check of the input audio level using just an oscilloscope. Can one look for clipping (or some other symptom) that indicates an overload of the D4D's audio input circuitry? I realize that it's possible to look at the RF output for signs of trouble but I'm wondering if it's possible to do so further upstream in the circuit. |
Use scope to check audio input level to D4D?
Hi All. I'm curious if there's a point in the D4D circuit that would allow for an easy check of the input audio level using just an oscilloscope. Can one look for clipping (or some other symptom) that indicates an overload of the D4D's audio input circuitry? I realize that it's possible to look at the RF output for signs of trouble but I'm wondering if it's possible to do so further upstream in the circuit.
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Re: Assembled HT-1A from USA location
John
Hi Adam. Just wondering if you have any idea when my rig will be shipped.? John K2JHU... On Thu, Oct 31, 2019 at 1:20 PM John Dorson <johnk2jhu@...> wrote:
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Re: Assembled HT-1A from USA location
Jim WB2LHP in MI
I don't own the HT-1A...I bought and built the D4D FT8 radio...I applied the recommended mods and it works very well...It will be my QRP Field Day rig using a solar panel and battery...Great quality and you can't beat the price...Jim On Thu, Oct 31, 2019 at 1:22 PM John <johnk2jhu@...> wrote:
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Re: Assembled HT-1A from USA location
John
Jim I just order he rig.So how well do you like the rig. Any thing I should know up front. John K2JHU... On Thu, Oct 31, 2019 at 12:43 PM Jim WB2LHP in MI <jmarco1955@...> wrote:
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Re: Assembled HT-1A from USA location
John
Adam the funds are on their way. John K2JHU... On Thu, Oct 31, 2019 at 1:05 PM Adam Rong <rongxh@...> wrote:
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Re: Assembled HT-1A from USA location
John
OK Adam. I will place my order today for the assembled?
HT-1A. Thank you. John K2JHU... On Thu, Oct 31, 2019 at 1:05 PM Adam Rong <rongxh@...> wrote:
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Re: Assembled HT-1A from USA location
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在 2019年11月1日,上午12:43,Jim WB2LHP in MI <jmarco1955@...> 写道:
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Re: Assembled HT-1A from USA location
Jim WB2LHP in MI
No...He is in China I believe... On Thu, Oct 31, 2019 at 12:23 PM John <johnk2jhu@...> wrote:
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Re: Assembled HT-1A from USA location
John
Thanks you Jim. Are they the ones in the UK. John K2JHU... On Thu, Oct 31, 2019 at 12:17 PM Jim WB2LHP in MI <jmarco1955@...> wrote:
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Re: Assembled HT-1A from USA location
Jim WB2LHP in MI
I also got no response from the US seller...Went instead to the designer and ordered direct...It was here in 2 weeks which I thought was very reasonable...I would order directly from CR Kits... On Thu, Oct 31, 2019 at 11:44 AM John <johnk2jhu@...> wrote:
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Assembled HT-1A from USA location
John
I have sent 2 e-mails to the USA site asking if they have any assembled radios with no response. I would really like one of these radios and thought shipping from US location?would result in a faster shipping time. Or should I just forget them and order from another location. John K2JHU... |
Re: D4D not working
Hi Bill,
The power meter is a cheap one, I didn't opened it but I assume it's? rms voltage sensing with some assumptions on how to change it into a power meter; the value yield it's very low in my case, but I don't think it has anything to do with the waveform. My computation was using the value provided by Adam as being the typical to be found (17 Vpp) and aplying an approximation to compute the rms voltage from it and the power from it, this computation yield 700 mW over 50 Ohms. Both are approximate figures. 73 de Pedro, LU7DID |
Re: D4D not working
开云体育
Both thermocouple and themistor type power meters measure True Power. Rather than indirectly measuring the power by measuring voltage and using a meter calibrated assuming a sinusoidal waveform.
73
Bill wa4lav
From: Fuqua, William <wlfuqu00@...>
Sent: Wednesday, October 16, 2019 3:44 PM To: [email protected] <[email protected]> Subject: Re: [crkits] D4D not working ?
This is a double sideband signal.
Remember, there are two signals and being generated and only one is being received unless the receiver on the distant end is a phase locked DSB receiver.
The calculation assumes a single sinusoidal waveform. Since the peak voltage is twice that of that for either sideband the power for the sideband which the distant station is receiving is 1/4 that calculated, or just a under 175 mW. If a thermocouple type of
power meter was used. You would divide by the result by 2. Naturally if it was a single sideband signal the results would be the same and as calculated.
73
Bill wa4lav
From: [email protected] <[email protected]> on behalf of Dr. Pedro E. Colla (LU7DID) via Groups.Io <lu7did@...>
Sent: Wednesday, October 16, 2019 9:47 AM To: [email protected] <[email protected]> Subject: Re: [crkits] D4D not working ?
Thank you Adam by the suggestion, this is the way I meassure the power output of my WSPR/FT8 beacon (Vpp*0,35)^2/RL in this case ((17V*0,35)^2)/50 would yield 700 mW approx.
The initial testing has been very much satisfactory, in reception as reported in pskreporter.info the greatest distance reported so far is some well over 19K Km (JA), on TX I was able to work a couple of PY stations (some 2000 Km away) when the band wasn't quite opened yet; what else can a small device like this be asked (attached is the pskreporter.info logbook over the past day or so, reports to my station is of the permanent beacon I have, not the D4D). I'd shared in some of the experiences in building the kit, the blog is in Spanish but Google translate will yield a half decent translation give or take a couple of words. Thank you for the very good support while building the kit. 73 de Pedro, LU7DID |
Re: D4D not working
开云体育
This is a double sideband signal.
Remember, there are two signals and being generated and only one is being received unless the receiver on the distant end is a phase locked DSB receiver.
The calculation assumes a single sinusoidal waveform. Since the peak voltage is twice that of that for either sideband the power for the sideband which the distant station is receiving is 1/4 that calculated, or just a under 175 mW. If a thermocouple type of
power meter was used. You would divide by the result by 2. Naturally if it was a single sideband signal the results would be the same and as calculated.
73
Bill wa4lav
From: [email protected] <[email protected]> on behalf of Dr. Pedro E. Colla (LU7DID) via Groups.Io <lu7did@...>
Sent: Wednesday, October 16, 2019 9:47 AM To: [email protected] <[email protected]> Subject: Re: [crkits] D4D not working ?
Thank you Adam by the suggestion, this is the way I meassure the power output of my WSPR/FT8 beacon (Vpp*0,35)^2/RL in this case ((17V*0,35)^2)/50 would yield 700 mW approx.
The initial testing has been very much satisfactory, in reception as reported in pskreporter.info the greatest distance reported so far is some well over 19K Km (JA), on TX I was able to work a couple of PY stations (some 2000 Km away) when the band wasn't quite opened yet; what else can a small device like this be asked (attached is the pskreporter.info logbook over the past day or so, reports to my station is of the permanent beacon I have, not the D4D). I'd shared in some of the experiences in building the kit, the blog is in Spanish but Google translate will yield a half decent translation give or take a couple of words. Thank you for the very good support while building the kit. 73 de Pedro, LU7DID |
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