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Re: wire jumpers PCB #u3s rev.3
#u3s
¿ªÔÆÌåÓýHi Martin,On 28/01/2018 22:00, Martin Wilens
wrote:
In the manual?assembly_u3s_r3_a4.pdf on page 10 there are several circled in yellow, the lowest is not clear to me. Flip the PCB over and you will see the unnamed terminals are on the same tracks as a named ones. Short answer yes you can connect +PA, +5v and Heat altogether. The unnamed terminals provide a method of creating tidy links at the same time? allowing an easy method of reconfiguration should your requirements change at a later date. See the diagram on page 11 Long answer, It has being found since writing of the document:- if you are using the OCXO option, using the same 5v supply as the MCU to feed the large current demands of the heater circuit is generally not recommended and may give rise to frequency drift on your transmissions. Even minute voltage fluctuations on the MCU and synthesiser supply voltage supply will give rise to this . It is recommended to feed the Heater circuit from a separately stabilised supply due to its high current demands. For the very best frequency stability then consider powering the +PA voltage from a separate regulated supply. It also gives you an opportunity to utilise a higher voltage regulator to increase RF power out if desired. (Subject to adequate heat sinking of the PA device(s)). See the section entitled 'Higher power output' near the bottom of page 16 Hans has produced FAQ and notes and there many threads on this forum regarding problems & solutions to the different causes of frequency drift. @Hans: is it possible to create a scematic drawing? including W0, W1, W2, W3, RF RFi and RF0? read the section on 'Hardware Requirements' Starting near the bottom of page 10 first. Then if you use a DVM / VOM meter to trace the links you should find, Links W0, W1 & W2, W3 are in parallel to the relay position RLY0 changeover contacts. The rule is if you are not fitting a relay in this position as you are not using the optional relay switch PCB then you should add the links to maintain continuity from the PA to the U3S on-board LPF and then again onward from the LPF to the RF pin. Fit a relay, fit no links as this will override the function of the relay contacts! The antenna connection required for the U3S in it's simplest form,? is to the RF Pin when no optional relay switch PCB is in-place. As shown on the diagram on the bottom of page 15. If you are using the optional relay switch PCB, there are several different filtered RF connection options, to terminal pins or different onboard connector options. This is described in that modules assembly instructions. Presently the only time a? 'kit builder' is required to make any connections to the 2x5 pin Backbone connector, that interconnects the stacking modules is when using the 5W PA Option . As detailed in that modules App Notes. (which contains the signal pins RFI(n) & RFO(ut) you mentioned) Thanks I hope that helps to clarify your questions. regards Alan |
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Re: Display flashing U3S
¿ªÔÆÌåÓýHi Mario,Have you tried squeezing the two boards together, in rare instance the interconnecting plug / socket can oxidise and cause a poor connection? Also as noted in the assembly manual, the PCB stand-offs supplied require an approx 1mm spacing be made between one half of the connector and pcb to ensure a good connection of the connector. regards Alan On 26/01/2018 21:46, df8dl@...
wrote:
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wire jumpers PCB #u3s rev.3
#u3s
In the manual?assembly_u3s_r3_a4.pdf on page 10 there are several circled in yellow, the lowest is not clear to me.
Are the unnamed pinnes above +Pa +5V and Heat parallel with +Pa +5V and Heat? In that case I can connect the unnamed pins all three together and have the +5V pin free for the powersupply.. @Hans: is it possible to create a scematic drawing? including W0, W1, W2, W3, RF RFi and RF0? It would be a bit more clearifying (at least for me) Thanks |
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Re: key short the first dash
¿ªÔÆÌåÓýHi A1aop,The solution to differing standards of key wiring has being reported before. The solution for straight keys / Keyers is to build a short adaptor lead, a 3.5mm line mono jack socket connected to just the Tip & Sleeve of a stereo 3.5mm jack plug and all is resolved, with the correct selection also in setup menu. And you can retain the use of the key with your previous radio(s) interchangeably. Hope this helps, Alan. On 28/01/2018 19:04, A1aop via
Groups.Io wrote:
Having the same problem no matter what paddle I use. Haven't tried an external keyer since the mono cord from the keyer shorts the rigs jack, unless I'm doing something wrong. |
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making mods to the clock kit
#clock
The clock and GPS kits are neat. Of course, I can't leave well enough alone so I am working on a portable gps/clock powered by four AA batteries with front panel switches to turn off the GPS and backlight and pots to control contrast and backlight brightness. From the various data sheets, it looks like the GPS board needs about 35mA while acquiring a signal and 25mA while tracking and the clock board, with the backlight turned off, needs 5mA. I think that the backlight requires 150mA at full brightness but different data sheets seem to say different things so I am not sure, So, question one:? can anyone confirm my estimates with measured currents used by GPS and clock kits?
Second question: since the GPS board uses 74ACT08s to drive the signal lines, I can drive more than one TTL load with the 1PPS and TxD lines, right? Third question: I am guessing that the clock kit iinterrogates the GPS to get the GGA data frame. Is there any reason why I can't passively listen for decode that frame with another device? 73 de bill K7WXW |
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Re: Might be useful for testing etc - The LED-O-METER
¿ªÔÆÌåÓýGreat idea Andy, Build it in a disused clear biro pen. It should get used more often than a screwdriver in the tool kit.
regards Alan On 27/01/2018 19:14, Andy G0FTD via
Groups.Io wrote:
Just been reading about constructors trying to trace RF in their circuits. |
Alan de G1FXB
Martin Wilens
bill K7WXW