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PostPosted: Wed Sep 26, 2012 9:04 am 
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Joined: Thu Aug 09, 2012 6:16 pm
Posts: 43
Hey Jim,

I know you have a lot on the plate now with the hardrock- but have you written a basic turn-up procedure for the DSP-610 that I have missed?

I have it assembled save for a couple of ECOs. I can infer a lot from the hardrock docs for the driver and amp- but not sure what to check and what order in the transceiver turn up process.

FWIW on ECOs - I saved the AS79's for last as I knew I'd be tempted to use the Ohm meter to check traces- and depending on range I suspect the current could damage them (sure does FST3125's et al). So I installed the chokes first, then the AS79 devices.

Has anyone turned one up yet?

73
Bill
N4BKT


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PostPosted: Wed Sep 26, 2012 11:04 am 
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Joined: Mon Jul 23, 2012 6:25 am
Posts: 1143
Is far as I know nobody but me has gotten on up and running. The receiver can 'hear' the 25 MHz clock at 25.000 MHz and at 50.000 MHz so you can use the signal stremgth indication to peak the variable caps in the LNA's and the IF's. The driver bias is 100 mA and the PA is 20MA per device. That should get you going.

73's
Jim WA2EUJ


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PostPosted: Wed Sep 26, 2012 11:51 am 
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Joined: Thu Aug 09, 2012 6:16 pm
Posts: 43
Thanks for the tips Jim- cross fingers. Still waiting for a programmer from Sure Electronics - got lost from china. I ordered the new Olimex PIC-KIT3 that Mouser has just added, around 30 bucks. Now that is 3 programmers I bought for one project. I needed anyway as my home built programmer is not up to task.

73
Bill

jimveatch wrote:
Is far as I know nobody but me has gotten on up and running. The receiver can 'hear' the 25 MHz clock at 25.000 MHz and at 50.000 MHz so you can use the signal stremgth indication to peak the variable caps in the LNA's and the IF's. The driver bias is 100 mA and the PA is 20MA per device. That should get you going.

73's
Jim WA2EUJ


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PostPosted: Wed Nov 28, 2012 9:50 am 
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Joined: Fri Aug 03, 2012 5:35 pm
Posts: 36
Like Bill, I'm a little nervious about turning up the PA. Is this a reasonable proceedure?

1. Turn all 6 bias pots to 0 v.
2. Pre-adjust RfPower (VR1 on mainboard).
What is appropriate? Half scale?
2. Adjust VR5 on mainboard for an appropriate voltage drop across R1A (1.5 v = 100 ma).
However, it appears that R85 would limit bias current to a max of 5 v / 47k = 0.1 ma.
3. Adjust VR5 on PAboard for an appropriate voltage drop across R6.
It appears that R6 would limit bias current to a max of 5 v / 10k = 0.5 ma.
What current is appropriate across R6?
4. Adjust VR1 through VR4 on PAboard for appropriate voltage drops across R1 through R4 (1.0 v = 20 ma).

Thanks in advance Jim.


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PostPosted: Wed Nov 28, 2012 2:44 pm 
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Joined: Mon Jul 23, 2012 6:25 am
Posts: 1143
First thing to do is set the bias on the pre-driver, Q10 in the main board. These are MOSFETs is the current flowing in the gate is 0ma, we set the drain current. So put an ammeter in the line feeding J13 (13V_DR) and set VR5 for 100mA with the TX Keyed in SSB with no audio.

Next see if you can measure the power from the main board into a 50 ohm load. Set RV1 for 1/2 watt output.

Don't worry none of the pot settings can blow the MOSFETs as long as they have a decent heatsink.

Now work with the PA board, hook to a load with an ammeter in the main line, power the 13V on the control jack not through the ammeter. Set all pots to minimum (CCW).

Put a 50 ohm load on the output and nothing on the input.

Increase VR5 for 400 mA, Then increase VR1 for 425mA, VR2 for 450mA, VR3 for 475mA and VR4 for 500 mA.

Now hook it up to the main board and it should make 50W on 10M and 30/35 on 6M

73's
Jim WA2EUJ


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