[Central-Electronics] 10b Operational

[Russ WQ3X]

Tom -

I had the same sort of experience as Jim did but with a CE 100V. Also about 
6 different problems causing the unwanted sideband not to be suppressed. I 
was lucky in that my 100V came with an old Navy spectrum analyzer and 
two-tone audio generator. (The previous owner was an ex-FCC engineer.) This 
made it much easier to troubleshoot. The owner had paid over $1000 to have 
it "restored" before I got it. As far as I could tell, nothing had been done 
to it except cosmetics. He got disgusted and just wanted to get it out of 
his house. I found switch connections with no solder on them from the 
factory, shorting to the walls and also broken solder joints inside the 
module cans due to the stiff solid wire used, etc. I did learn a lot about 
phasing transmitters though!

When listening in a receiver that is that close I would think that you would 
be able to hear the unwanted sideband. Maybe try grounding the antenna input 
of the receiver with a short wire. Transmit into a dummy load at very low 
power. If you can get the signal down to where the S-meter is not pinned all 
the time then you can use that as Jim says. This group is way too quiet so 
please keep us posted on your progress. 73.

Russ WQ3X


----- Original Message ----- 
From: "Jim Candela" <jcandela at prodigy.net>
To: <telmore1964 at yahoo.com>; <central-electronics at mailman.qth.net>
Sent: Friday, October 30, 2009 8:07 AM
Subject: Re: [Central-Electronics] 10b Operational


> Tom,
>
>     Your power sounds a bit low to me, but since I don't own a 10b, I will 
> defer the 20m power to those that have first hand experience. As for 
> sideband rejection, have you done the setup of the sideband circuits as 
> described in the owners manual? Basically with a pure sine wave input you 
> should see a CW output without modulation that is shifted from the carrier 
> frequency by the frequency of the audio tone input.
>     When listening on a SSB receiver, and switching SB1/SB2 on the 10b, 
> you will hear both upper and lower sidebands. The hope however is that the 
> unwanted sideband will be at least 4-5 S units weaker (30db or more). The 
> unwanted sideband might also sound weird since it will not present the 
> full frequency response when compared to the desired sideband.
>      My initiation into my first 20a had no less than six issues with the 
> carrier null, audio phase shifter, and balanced modulator circuitry. That 
> rig literally kicked my arse. I put it on the shelf several times, but I 
> was compelled to start again, and again...eventually I prevailed. Then I 
> hear others just turn on a Ebay 20a, or 10b, and it works great! Your 
> mileage might vary. :-)
>
>  Good Luck with your  10b,
>
> Jim
> WD5JKO
>
>
>
> ----- Original Message ----
> From: Thomas Elmore <telmore1964 at yahoo.com>
> To: central-electronics at mailman.qth.net
> Sent: Thu, October 29, 2009 10:35:38 PM
> Subject: [Central-Electronics] 10b Operational
>
> Recently, I picked up a 10B exciter that had been in long term storage. 
> After replacing all the electrolytics I seem to have the unit operational. 
> I had to replace the control relay which I understand is a common item 
> that fails. Also I found a great VFO from someone on this list to help get 
> me going. I currently only have 20 meter coils in this unit and get about 
> 4 to 4 1/2 watts out according to the Bird. Is this a common power output 
> for 20 meters or should I see closer to 10 watts? I understand power drops 
> off on the higher bands and I was curious as to what frequency this starts 
> to occur.  My last question is if I choose either sideband 1 or 2 position 
> and and null the carrier out and set the carrier level control to 0 and 
> listen to my transmit audio on my 75S3 receiver in say the usb position it 
> sounds the same if I change change the 10b sideband control back and forth 
> while transmitting. It seems to me I as ?I change the sidband control on 
> the 10b
> I would have to do the same on the receiver to get them to match up?
>
> Thanks
>
> -tom
>
www.qsl.net/donate.html