|
Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
|
Thread Tools |
27th Mar 2021, 12:25 am | #1 |
Diode
Join Date: Mar 2021
Location: Salt Lake City, Utah, USA
Posts: 8
|
Trio 9R59. First Restoration - Need Direction
For my first ever radio restoration project, I bought a used Lafayette HE-30 (Trio 9R59). Overall it is in good shape, but upon opening it, I noticed the 5Y3 rectifier tube was missing. On the under-side, I noticed someone had installed a voltage regulator (probably to improve drift). I later noticed that there were 2 diodes soldered to the bottom of the rectifier socket, I assume as a rectifier tube replacement.
A couple of questions: 1. Are 2 diodes sufficient? Back from my electronics classes, it took 4 diodes to make a full bridge rectifier. 2. What should I check before my initial power on? The radio has a 1A blown fuse in the socket, but I can't imagine that is a large enough fuse for this radio. Thanks |
27th Mar 2021, 12:48 am | #2 | |
Heptode
Join Date: Mar 2017
Location: Cedar Grove, Wisconsin, USA.
Posts: 823
|
Re: Trio 9R59. First Restoration - Need Direction
Quote:
Replace the fuse and use dim lamp limiter to check the set for a over current condition. Use a 60 watt incandescent lamp. There's plenty of information in the radio forums regarding that method to prevent further damage. Dave, USradcoll1 |
|
27th Mar 2021, 8:47 am | #3 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,548
|
Re: Trio 9R59. First Restoration - Need Direction
The 5Y3 is a full-wave rectifier, not a bridge so two diodes are fine.
__________________
There are lots of brilliant keyboard players and then there is Rick Wakeman..... |
27th Mar 2021, 2:14 pm | #4 |
Nonode
Join Date: Mar 2010
Location: Dukinfield, Cheshire, UK.
Posts: 2,034
|
Re: Trio 9R59. First Restoration - Need Direction
The 1 amp fuse should be more than enough for a receiver like this in normal operation.
__________________
Andy G1HBE. |
28th Mar 2021, 1:04 am | #5 |
Diode
Join Date: Mar 2021
Location: Salt Lake City, Utah, USA
Posts: 8
|
Re: Trio 9R59. First Restoration - Need Direction
Thanks for the feedback. I found buried in the manual that it wants a 2A fuse. I was able to power up and no sparks or smoke, just the dial lamp came on, so I'm off to a good start. Now to run some tests. I've been cleaning the case & chassis, but I'll almost be disappointed if I don't have to fix anything inside
|
28th Mar 2021, 6:30 pm | #6 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,951
|
Re: Trio 9R59. First Restoration - Need Direction
There's loads of info out there on the Trio 9R-59 range of radios to help you with your restoration.
A couple of things to think about 'further down the line' - [1] the coils in the RF box were slathered with a wax that - over time - absorbs moisture and degrades - this reduces the 'Q' of the coils to the point where the local-oscillator can stop oscillating on the highest-frequency band. Gentle directed heat from a hair-dryer, and the use of a "Q-tip" cotton-bud [appropriately named!] to wipe away the wax as it softens can really improve matters. [2] there's a yellow wire that connects the antenna tuned-circuit to the 'Ant Trim' panel-control; this runs through the oscillator-compartment of the RF box. Stray capacitance between this wire and the oscillator tuned-circuitry can mean that - on the highest-frequency range - the "Ant Trim" control will shift the LO by quite a few KHz, which makes tuning SSB stations on 21 and 28MHz a real needs-three-hands game. Re-routing the yellow wire to the Ant-Trim control so it's outside the RF-box really improves overall 'driveability'. And if yours doesn't have the neon-glow regulator for the LO/BFO's HT-rail - it's really worth fitting it if you want stable reception of SSB stations. |