Podcasting since 2005! Listen to Latest SolderSmoke

Monday, July 22, 2019

Making Fish Soup from Herring and Tuna (How to Build a Fish Soup 10 Transceiver)


Just in case some other fanatic someday thinks about trying to turn a Herring Aid 5 and a Tuna Tin 2 into a Fish Soup 10. This will also serve as a note to myself on how I did this.  Above are my suggestions on how to get the VFO signal into the transmitter and the receiver.  Both RX and TX can easily be returned to their original condition. 

Saturday, July 20, 2019

A Frequency Readout for the Fish Soup 10 (with cool BLUE numerals)

Note the cool BLUE numerals.  They represent 7040, 7050, 7060, 7070.  The little black "pointer" is from a power cord wall fastener.  My tuning cap has a nice reduction drive -- the pointer follows the movement of the capacitor blades.  The VFO is very stable. 

Simplicity is a virtue.  CW is, I think, outmoded and kind of absurd (one letter at a time?  really?), but it does allow for extreme simplicity.  Using a rig with just 10 transistors, putting out half a watt of RF,  I am regularly communicating with people.  This is what I like about CW.   

I've had about 12 solid contacts with this rig since putting it on the air earlier this month.  The VFO was a huge improvement over being crystal controlled. Crystal control was OK back when receivers were broad and hams tuned around for replies, but those days are gone.  Getting the transmit offset set correctly was another huge improvement. 

From Bill's Apollo 11 Scrapbook


From the Apollo 11 scrapbook I made back in '69. I got the date for the moonwalk wrong. But hey, I was only 10 years old.

Thursday, July 18, 2019

Video of Fish Soup 10 QSO (from N3MLB)



So cool.  During our QSO on 40 Meter CW today, N3MLB recorded it and put it on YouTube.  This is what my 500 milliwatt Fish Soup 10 rig sounds like in Pennsylvania. Thanks a lot Chris. 



From Chris's QRZ.com page: 




Monday, July 15, 2019

The "Fish Soup 10" Homebrew QRP CW Transceiver


The box with the two grey knobs on the left is the Herring Aid 5, the receiver that took me 38 years to complete. The box on the right is a VFO I originally built for my first BITX40Module -- it started out around 4 Mhz but I pulled turns off the coil until it was in the 40M CW band.  The Altoids in near center has the buffers -- a 40673 MOSFET and a 2n3904 BJT. The box in the back holds the Tuna Tin 2.  There the oscillator has been reconfigured as an amp.  A relay switches the output from the buffers between the receiver and the transmitter.  That big switch in the center switches the antenna and the 12 V for T/R.  The circular black thing is piezo buzzer used for CW sidetone -- I have it glued to the board upside down to keep the volume down. 

The whole thing is mounted on a kitchen cutting board.  A breadboard! 

The most difficult part of all this was getting the needed 800 Hz drop in TX freq on transmit.  You need to do this with a rig like this or else you won't be in the other fellow's passband.  I did a lot of cut and try -- in the end I put a 5 pf cap across the coupling cap from VFO to buffer.  This 5 pf cap switches in on transmit via a small relay.   It works.  I just spoke to N8AFT out in Columbus, Ohio and I was in his passband.  

So five transistors in the receiver, two in the transmitter and three in the VFO/Buffer. So it is the  Fish Soup 10.  

It puts out about half a watt.  On CW.   I am feeling virtuous and vaguely superior. I've made several more contacts.  It all works very well and is a lot of fun. 


Sunday, July 14, 2019

Feedback on QSOs -- Listeners are Listening

On opposite coasts and with rigs at opposite ends of the technology spectrum, Pete and I have been putting new homebrew rigs on the air.  I'm working on a QRPp transceiver using 10 transistors.  Pete is working on an SDR rig that must use, what?,  thousands or millions of transistors.  

We've both been getting nice feedback, often from SolderSmoke podcast listeners.  Above you can see my 8 July notes on a contact with K3QP.   I was running about 1/2 watt, crystal control, from the Fish Soup 7 combo rig. 

---------------------------------
In an earlier post I mentioned Pete's success in working coast-to-coast on 40 SSB with his homebrew SDR RADIG.  Turns out that someone in St. Louis heard the contact: 

From: Steve 
Sent: Saturday, July 13, 2019 6:16 PM
To: Pete
Subject: Friday QSO

Hi Pete

Heard your QSO to Virginia last evening. Conditions were rough but could hear good enough. I’m located west of St Louis and was outside portable with KX2 and wires tossed in a couple trees. Tried to tail end but of course my signal was not good for you in California.

I really am amazed at the work you put into your projects, websites, and podcast. Can’t thank you enough. Please keep it up.

I worked at McAir in St Louis and spent many hours in the MDEC building St Charles. That was in the late 80s.

Steve
K0SAM
----------------------------------

Finally, earlier in July I had a contact with K1PUG.   Someone north of the border heard us: 

On Sunday, July 7, 2019, 01:17:47 PM EDT, Dave  wrote:

I heard your QSO with Hank K1PUG at my cottage in Canada (FN15ac) this morning. I wondered why you were so faint (since I had been getting good reports with 5W into your area) but when I read this morning’s entry in SolderSmoke, and saw you were 750mW, all became clear.

73,
Dave KM6CPF / VA3NIA

Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column