HobbyPCB.com

Built by Hobbyist for Hobbyist!
It is currently Mon Nov 20, 2017 1:03 am

All times are UTC - 5 hours




Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: RS-UVPA Options
PostPosted: Tue Aug 29, 2017 7:16 am 
Offline

Joined: Thu Aug 18, 2016 9:05 pm
Posts: 8
I see different transceiver options for the RS-UVPA Power Amp on the Web site. What are the differences between the RS-UV3 Rev. C and the Hamshield options ? I have both of these transceivers and I'd like to be able the switch and use the same Power Amp. for both transceivers as required. Is it possible to use the same Power Amp. for the RS-UV3 and the Hamshield, how involved is it to do so and what option should I order to accomplish this ? Thank you in advance.

73,

Rej. VE3MPV


Top
 Profile  
 
 Post subject: Re: RS-UVPA Options
PostPosted: Tue Aug 29, 2017 9:10 am 
Offline

Joined: Mon Jul 23, 2012 6:25 am
Posts: 881
Hi Rej,

The RS-UVPA is designed to plug directly into the RS-UV3. All inter-connecting signals are passed between the two boards on plug-in headers. Both of those boards can slide into an extruded enclosure making a nice compact 5W, three band transceiver.

When you order the Hamshield option, you get an extra SMA connector and a short coax jumper that connects the antenna jack of the Hamshield to the radio port on the US-UVPA. Control signals are more complicated. The amp requires 3 control signals 2M PTT, 1.2M PTT and 70CM PTT. These are active high 3.3V logic signals that activate the amplifier on the required band. For my Hamshield, I use an Uno Plus (https://www.hobbypcb.com/products/tools ... o-improved) which has the ability to use 3.3V signalling. If none of the control signals are active the LNA is placed in the RX line.

The sketch you use to run the Hamshield must be modified to send the proper control signals to the RS-UVPA and the power on the Hamshield must be set at 200mW to properly drive the RS-UvPA.

There are a couple issues that will make using the RS-UVPA for both the RS-UV3 and the Hamshield difficult.

1. The LNA gain is set to just a few DB for the RS-UV3 since it has a decent LNA already. For the Hamshield, clearing SJ3 of solder, increases the LNA gain to about 10 dB which greatly improves the Hamshield's RX sensitivity and noise figure.

2. If you install the 'RADIO' SMA jack you have to bridge SJ1 to make the connection to the jack this means you won't be able to connect the RS-UV3 directly to the RS-UVPA. You can use the coax jumper to connect the RS-UV3 and RS-UVPA.

3. Control signals - if you don't plug the RS-UVPA directly into the RS-UV3, you'll need to make a control cable to take the signals on the AMP header over to the RS-UVPA. I do this for testing and it works OK.

4. Switching - You'll need a method of switching RF and control signals between the Hamshield and the RS-UV3.

73,
Jim WA2EUJ


Top
 Profile  
 
 Post subject: Re: RS-UVPA Options
PostPosted: Wed Aug 30, 2017 7:54 am 
Offline

Joined: Thu Aug 18, 2016 9:05 pm
Posts: 8
Hello Jim,

Thank you for the prompt reply and the technical details. I was hoping for a simpler way to interchange the RS-UV3 with the Hamshield board; but, I realise that both transceiver boards are significantly different and do require specific connections to operate properly with the RS-UVPA add-on board. Considering your expertise and experience, I'll get a Uno Plus with the RS-UVPA Hamshield version to experiment with. Later, if I decide to use the Power Amp with the RS-UV3, as it was intended to be used with, I'll change the LNA setting, inter-connect the plug-in headers and Bob's your uncle. Fell free to add or comment on my plan.

73,
Rej. VE3MPV


Top
 Profile  
 
 Post subject: Re: RS-UVPA Options
PostPosted: Thu Aug 31, 2017 5:18 am 
Offline

Joined: Mon Jul 23, 2012 6:25 am
Posts: 881
Hi Rej,

I just went through a similar exercise to see how to interface a Hamshield to the RS-UVPA. I first built a stack with the Arduino Uno on the bottom, then the Hamshield then a DFRobot LCD/Keypad on the top.

I needed an extra control line and don't plan on dimming the backlight on the LCD so I cut the pin on D10 on the DFRobot so it doesn't connect to the Hamshied or Arduino. Then I jumpered GPIO6 (squelch detect) to D10 on the Hanshield so the Arduino can tell if the Hanshield's squelch is open.

I also put a 3.9K resistor to ground on the DFRobot LCB's AD0 to ground to scale the analog voltage to 3.3V instead of 5.0V.

Struggling with the Hamshield Arduino library and the forums I wrote a basic sketch that steps through some memory channels, draws a signal strength bar-graph and indicated if the Hanshield is TXing or RXing.

Then I added the RS-UVPA and connected The Arduino's D11 to Pin 4, D12 to Pin 3, D13 to Pin 2 and GND to Pin 1 on the RS-UVPA JP1 Header. These are the 144, 220 and 440 band keylines (active high, 3.3V max). The sketch selects the appropriate keyline before switching to TX.

I can give you more details we can even setup a Wiki site is you want a place to collaborate/deposit design info.

73,
Jim WA2EUJ


Top
 Profile  
 
 Post subject: Re: RS-UVPA Options
PostPosted: Fri Sep 01, 2017 6:46 am 
Offline

Joined: Thu Aug 18, 2016 9:05 pm
Posts: 8
Hello Jim,

The order is in and I'm anxious to test the boards and exploit their potential. Thank you for your support and insightful comments.

73,
Rej. VE3MPV


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group