Skip to main content

About 2/3 done with the Wiring

It actually rained the night before last and so cooler temperatures yesterday but a lot more humid. 

We meet characters in our life we never forget and as such was an older woman our family knew when I lived in St Louis. 

She was missing her two front teeth, so the words had a distinct twang. Bless her soul, she had a metric for such weather: it was either a two-bra day or three bra day depending on how humid it was and that drove the number of bra changes.  In her terms, yesterday was a three-bra day.

In Italian she would be described as:
"una vecchia senza denti"

Much progress on the wiring and it is nice to see when a plan comes together. I did a lot of planning so the Digi-LO/BFO would be close to the required ports on the main sub-chassis assembly. Six-inch cables do the deed.


Perfetto!

Under Chassis Wiring.

The assembly with two power resistors and electrolytic capacitor took almost an hour to wire up. This is a power distribution hub and takes the 280 VDC and drops it to 185 VDC for the screen voltage for the lower-level tubes while the 280VDC is the screen voltage on the 12GE5. There is a small relay just above the electrolytic cap that is a SPDT and when engaged on transmit supplies the 280VDC to the 12GE5 screen. 

This board is also a convenient junction termination location for the power on/off switch. Other junctions are for the Filament Voltage, the Bias plus Control Relays. 

I also built and installed a parasitic suppressor in the plate lead which is nothing more than two 100 Ohm 1/2-watt resistors in parallel shunted by a three-turn coil. This is an oscillation killer in the VHF range.

Well, after all that we found we had a short in the wiring as it was permanently in PTT. I checked all the wiring and didn't spot any misconnection but did unsolder a lot of stuff. So, a bit of a delay as I repair what I had undone. Mysteriously, the short is cleared but still need a clean-up. When it rains it pours, and it did! 

Them that know can make things go.

73's
Pete N6QW




Popular posts from this blog

Tidbits from Saturday and a visit to a ham event.

Using AI as a design Tool. Caveat Emptor

Meet Herman, my newly AI generated helper for the N6QW, Newbury Park Laboratories

So be over with the old radios... A comment to me

Advancing the Final Assembly of the Mostly Vacuum Tube Transceiver

Mid-course in the wiring process on the mostly Vacuum Tube Transceiver.

Cosmophone 35. Commencing the Final Assembly Stage of the Hybrid Wireless.