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Re: Pulling Crystal Frequency in VXO
Are boards available for these transceivers
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Doug Hendricks
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#9692
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Re: AA7FO VXO Crystal Table, First Pass
John et al, I must apologize.? I just mentioned the C language because I do all my stuff in it.? It's a poke at the Python and CS computer language wars.? Very sorry. It was assumed on my part that
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chuck adams
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#9691
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Re: Pulling Crystal Frequency in VXO
Folks, many years ago, Luc F6BQU designed "Le Forty", a 40 meter transceiver using a VXO. In order to enlarge the range he used two chokes in series but placed parallel to each other in the PCB, so
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Jon EA2SN / AE2SN
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#9690
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Re: uP40 Transceiver
Hi Mike I've used the TL974 in several project without issue. I use it because it's very good value for money having quite low noise of 4 nV. It's main shortcoming is that it cannot source more than a
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vk7ian@...
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#9689
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Re: AA7FO VXO Crystal Table, First Pass
For those of us not literate in C, you can do the same thing with an intermod calculator program - I use a freebee one called "PRFINTERMOD, freely available on the web. John, VK4TJ
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John Kirk
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#9688
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Re: VXO /IF combo schemes
My bad. I should have said NorCal 38S. Not sure our scope here includes thermion devices. (-: Yes I referenced bulk acoustic wave filters on a chip as something I was engaged developing. In great
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Curt
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#9687
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Re: VXO /IF combo schemes
Oh, oops.? When I was refering to a 38S I was going further back to the Hallicrafters tube receiver back in the 50s, the 1950s.
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chuck adams
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#9686
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Re: VXO /IF combo schemes
On the 38S it was designed around that large IC that who knows its its still available. Otherwise it's a normal ne602 type transceiver. That vxo and IF combo meanwhile are useful. I recall my rig
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Curt
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#9685
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Re: Pulling Crystal Frequency in VXO
All, If I were to build an SST or similar rig for 20-Meters, I would use the following crystals. IF, 3.932 MHz crystals, Mouser part number 520-HCA393-17X and for the VXO, 18 MHz crystals, Mouser part
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Jim Kortge, K8IQY
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#9684
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Re: AA7FO VXO Crystal Table, First Pass
Thanks for the great info Chuck. Good job on your C program. This will definitely help me out and I appreciate it. 73, Alan, N8WQ
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Alan N8WQ
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#9683
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Re: VXO /IF combo schemes
Curt, Thanks for the info and your observation about selectivity. I am looking at the 38S schematic. It is an interesting design. 73, Alan, N8WQ
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Alan N8WQ
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#9682
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VXO Crystal Table posting correction
1.? It's the WARC bands.? Typo on my part. ??? I'll send back my UIL typing championship trophy. ??? Now you know why my postings are so long.? :-) 2.? I restricted the band search to the CW
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chuck adams
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#9681
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AA7FO VXO Crystal Table, First Pass
If I did it, do I get to name it?? :-) I went to Aliexpress and ebay and looked up available crystal frequencies for off the shelf values.? I cheated and added one more frequency from the 1W values
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chuck adams
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#9680
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Re: VXO /IF combo schemes
Alan Some info here. Presuming industry may still have these crystals. https://www.qrp4u.de/docs/en/tables/index.htm Did my search on qrp vxo if combinations Note when IF must go up there is
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Curt
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#9679
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VXO /IF combo schemes
Gang, Has anyone created a excel spreadsheet where one can experiment by either plugging in given crystal frequencies for the VXO and IF per Band or a table of popular crystal frequencies? Just
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Alan N8WQ
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#9678
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Re: PCBWay charges
Ask and ye shall receive: <https://www.qsl.net/aa7fo/k7qo-crystal-parameters.pdf> The equations that I derived while a student were about 1962.? Eons ago. -- chuck adams, aa7fo QRP WAS 17m started
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chuck adams
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#9677
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Pulling Crystal Frequency in VXO
Found the following on the internet for those interested in such stuff for the SST project.? FYI and shown without any attempt at organization. The following shows quantitative results using two
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chuck adams
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#9676
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Re: PCBWay charges
Hi Chuck, Is there some way we can get a copy of your article? Thanks... Alan, N8WQ
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Alan N8WQ
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#9675
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Re: uP40 Transceiver
Ian, What is your experience with using TL974 in the AF gain stage? When I tried those, the clicking sound from WiFi detection was very annoying. This seems to be a "feature" of the whole TL97x
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vbifyz
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#9674
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Re: uP40 Transceiver
Hi Mike The audio output has been divided into two channels of PWM.? One is for the high 6 bits and the other for the low 6 bits - it is a 12 bit value. This allows each PWM to be clocked at 64 times
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vk7ian@...
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#9673
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