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Re: Ramsey HR-1
Hi Charlie
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I have one, let me dig out the info on it, will post tomorrow Al ve3gam -----Original Message-----
From: lgriggs@... Sent: Thursday, July 04, 2019 6:25 PM To: [email protected] Subject: [qrp-tech] Ramsey HR-1 Does anyone have information on this unit? A schematic, parts list, etc? Charlie, H3UIM |
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2N2-40+ QRP-Transceiver, troubleshooting
Hi,
i'm currently building a 2N2/40+. Here I use the circuit diagrams "2N240+AA-DA.SCH; 02012002" from the page " As layout I use the K3PEG template Verson 4, April 27, 2005 So far I have finished the layout segments: 9: Audio Amp, RX Mute, Audio Preamp, 8: Rx Local Oscillator 3: IF Amp +40dB, Variable Xtal Filter, Mixer Amp +9dB 2: RX Input Filter, RF Amp +12dB, DB Mixer 4: Varactor Tuned, Buffered VFO Now the receiver should be checked. However, there seem to be some bugs that I have to find and fix bit by bit. Since I'm not good at troubleshooting, I present the problems I noticed here. I want to start with the VFO, which doesn't provide enough output voltage from my point of view. First the DC voltages from the circuit diagram were checked. Here are the measured values: Q1: B=4.34, C=6.90, E=3.76 Q2: B=4.02, C=13.84, E=3.40 Q3: B=3.40, C=13.48, E=2.75 D5: K=6.90 D6: A=0.69 Some pictures of the signals are stored in the album "DL2KI 2N2/40+": pic01: C9/C13 pic02: Q1 B pic03: Q1 E pic04: Q2 B pic05: Q2 E pic06: Q3 B = Q2 E pic07: Q3 C Maybe someone can have a look at the pictures and give a hint for further troubleshooting. If additional measured values are required, please send me an info. Many thanks in advance and i hope my translator works well ;-) 73, Wolfgang DL2KI |
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Re: Homebrew receiver - Heard a net on the wrong band
ajparent1/kb1gmx
The ubitx filter are low pass design. The Ubitx has NO band pass filters.
The Bitx40 current has a filter that has a peaked low pass. The really old versions of the bitx20 had a true band pass. if your VFO is in the 5Mhz range you will see 9mhz IF +vfo and 9MHZ if - VFO there is no mystery as hams have use that trick for year to get dual band radios. So first you bandpass filter is very poor is you can hear 80M at all! Second Your BFO is likely not set right and 20M (nomally USB) the product detection is suffering and since 80M is nominally LSB if it sounds better fix the BFO. FYI harmonics of SSB signals are unintelligible, always. You are getting an IMAGE response due to poor input filters. Allison -- Please reply on the group, no private emails we as a group share info that way. |
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Re: Homebrew receiver - Heard a net on the wrong band
Hi Mark,
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That is what I thought, too. I am using low pass filters (per band) external to my uBitX to deal with the poor spectral performance (I have the version 3). I expect to go to bandpass filters just to promote even better spectral performance. using external filters is a legacy approach and I use external filters with all of my transmitters and by the way they, are inline on receiver too. 73, Bill KU8H On 7/3/19 10:45 AM, Mark G?NMY wrote:
I always thought the uBitx filter was a lowpass filter not a bandpass --
bark less - wag more |
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Re: Homebrew receiver - Heard a net on the wrong band
Mark G?NMY
I always thought the uBitx filter was a lowpass filter not a bandpass
filter I could be wrong though. I would suggest QRP-Labs bandpass filter kits very cheap ========================================================================================================================================================= - *May the MORSE be with you!* - *My Ham Radio Blog <>* - G?NMY G-QRP #12875 <> - G-QRP clublog <> - UKSMG club log <> - *???q? ??o p??oq??? ? ?nq ? ???? ?s?? ??? s? s???* - [image: UKSMG.ORG] <> - *UKSMG.ORG <>* On Wed, 3 Jul 2019 at 15:35, Richard Seguin <richard.seguin@...> wrote: Thank you for all of the replies. This makes perfect sense now. |
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Re: Homebrew receiver - Heard a net on the wrong band
Richard Seguin
Thank you for all of the replies. This makes perfect sense now.
I'll design a better bandpass filter (maybe just one band instead of all of them). On Wed, Jul 3, 2019 at 11:02 AM John Marshall KU4AF <johnmars@...> wrote:
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Re: Homebrew receiver - Heard a net on the wrong band
So, the problem must be the?? Ubitx bandpass filter is not right, or not a very good bandpass filter.
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73, Gary WB6OGD On 7/3/2019 7:02 AM, John Marshall KU4AF wrote:
Ubitx bandpass |
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Re: Homebrew receiver - Heard a net on the wrong band
Richard,
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It's an image rather than a harmonic. Harmonics are integral multiples of a frequency so 3725, 7450, 11175, 14900, etc. When your receiver is tuned to 14265, the Si5351 local oscillator runs at 5265 kHz. That frequency is subtracted from 14265 in the mixer to give 9000 kHz ( 14265 - 5265 = 9000 ). If a 3725 kHz signal is present at the mixer input, it will mix with the 5625 kHz local oscillator to give output at 9000 ( 3725 + 5265 = 9000 ). This is a classic issue with superheterodyne receivers. The mixer can't discriminate between those two input frequencies so it's up to the tuned circuit(s) between the antenna and the mixer to select the one you want and suppress the other. You may be able to work around the problem by choosing a different local oscillator frequency. For example, you could set the Si5351 to 23265 kHz ( 23265 - 14265 = 9000 ). That moves the image frequency to 32265 kHz, which may be easier to suppress and will likely be free of interfering signals, too. 73, John, KU4AF Pittsboro, NC On Jul 3, 2019, at 9:20 AM, Richard Seguin <richard.seguin@...> wrote: |
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Re: Homebrew receiver - Heard a net on the wrong band
Scott McDonald
Hi Richard.
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As I expect you¡¯ll hear from many folks, you are hearing the sum and difference of 9 MHz and your 5.265 vfo. If there isn¡¯t a tuned circuit in your RF amp, the uBITX front end will do a good job of excluding non 0 to 30 MHz signals but won¡¯t offer any selectivity to select between the sum and difference frequencies, ie 80 and 20 meters. A tuned circuit will fix that. You¡¯ve rediscovered the magic that drove the use of 9 MHz filters and 5 MHz vfos many years ago. Why it sounds better one way than the other is anybody¡¯s guess but it may well sound different with some front end selectivity. 73 Scott Ka9p On Jul 3, 2019, at 8:20 AM, Richard Seguin <richard.seguin@...> wrote: |
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Re: Homebrew receiver - Heard a net on the wrong band
Richard Seguin
Certainly,
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* Superheterodyne design with diode ring mixers * IF is 9 Mhz * LO is produced by a Si5351 (square wave LO) Block diagram: ANT -> Ubitx bandpass -> RF amplifier -> DBM -> Crystal filter (4 pole) -> IF amplifier -> DBM -> Near unity gain amplifier (for proper termination of the mixer) -> Audio amplifier -> Headphones On Wed, Jul 3, 2019 at 10:14 AM Michael Maiorana <zfreak@...> wrote:
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Re: Homebrew receiver - Heard a net on the wrong band
Can you give us more info about your receiver?
Mike M. KU4QO On Wed, Jul 3, 2019 at 9:03 AM Richard Seguin <richard.seguin@...> wrote: Good morning, |
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Homebrew receiver - Heard a net on the wrong band
Richard Seguin
Good morning,
I have a weird issue that I would like to ask you folks about. Yesterday, I heard a net that I thought was on 14265 khz. I reached out to one of the operators because I thought that it was weird that the particular net wasn't at its usual frequency on 80 meters. It turns out, I was actually listening to a harmonic and that the net was on 3735khz. Here is the weird part, it sounded better on 20 meters than 80... I confirmed with a signal generator that the area that I was tuned is an actual harmonic. Have any of you homebrewers run into this issue? Richard (VE1XOR) |
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Re: Kanga LCK transceiver kit
Mark G?NMY
find attached sprat60 with LCK info
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72 g0nmy - *May the MORSE be with you!* - *My Ham Radio Blog <>* - G?NMY G-QRP #12875 <> - G-QRP clublog <> - UKSMG club log <> - *???q? ??o p??oq??? ? ?nq ? ???? ?s?? ??? s? s???* - [image: UKSMG.ORG] <> - *UKSMG.ORG <>* On Tue, 2 Jul 2019 at 15:22, Neil Goldstein <neilgoldstein@...> wrote:
The LCK was a G-QRP project published in Sprat, their newsletter. I found |
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Re: Kanga LCK transceiver kit
Here are the manuals that I have. I hope that helps.
Mike M. KU4QO On Mon, Jul 1, 2019 at 5:08 AM Claude-Alain Baumgartner via Groups.Io <cab0310@...> wrote: Hi all, |
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Re: Kanga LCK transceiver kit
This makes it difficult for us to experiment with radio kits.
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Communication with project website. Visit: Oliveira PY2-255SWL Call Sign PU2OLT RX Morphy Richards 27024 RX/TX YAESU FT817D RX/TX YAESU FT897D Blog: Em ter, 2 de jul de 2019 ¨¤s 11:22, Neil Goldstein <neilgoldstein@...> escreveu: The LCK was a G-QRP project published in Sprat, their newsletter. I found |
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Re: Kanga LCK transceiver kit
The LCK was a G-QRP project published in Sprat, their newsletter. I found
it listed on an archived page of the Kanga-USA site, but no instructions or anything. I would contact the G-QRP folks and ask if anyone has documentation. Let us know how it goes. Looks like an interesting project. The owner of Kanga-USA has shut down for health reasons but you might also try there. Sent from my VIC20 - Neil Goldstein Radiokitguide.com |
wb6ogd
Oliveira
Neil Goldstein
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