06-02-2021, 10:36 AM
Hi Strelok
In the London Power kits, all power resistors are elevated by 6mm (0.25") and the kit notes show a little drawing and directive for this.
Decoupling resistors in preamp kits are all 600mW and do not get anywhere near to that dissipation during normal use, and therefore do not require elevation, nor do they have to be flame-proof types.
All electronic components use their leads as heat sinking, which is why you see such fat leads on zeners and high-current diodes. In some cases, it is advisable to leave a long lead on these components so their heat can be dissipated properly. In London Power kits, we use large solder pads wherever possible, both for heat dissipation and simply because a large solder connection will long out-live a small one.
Formed leads are usually to protect the point of exit of the lead from the component body. For example, epoxy-dipped capacitors or enamelled resistors have an outer coating that "wets" and flows out over the lead, just like proper solder connections. This flowed covering over the lead wire is fragile. Were you to bend the lead right at the body, the thinner part of this covering would fracture and the moisture seal would be compromised. Forming the lead before installing the part moves the stress point to the point of forming and retains the moisture resistance, and thus preserves the life expectancy of the component.
Have fun
In the London Power kits, all power resistors are elevated by 6mm (0.25") and the kit notes show a little drawing and directive for this.
Decoupling resistors in preamp kits are all 600mW and do not get anywhere near to that dissipation during normal use, and therefore do not require elevation, nor do they have to be flame-proof types.
All electronic components use their leads as heat sinking, which is why you see such fat leads on zeners and high-current diodes. In some cases, it is advisable to leave a long lead on these components so their heat can be dissipated properly. In London Power kits, we use large solder pads wherever possible, both for heat dissipation and simply because a large solder connection will long out-live a small one.
Formed leads are usually to protect the point of exit of the lead from the component body. For example, epoxy-dipped capacitors or enamelled resistors have an outer coating that "wets" and flows out over the lead, just like proper solder connections. This flowed covering over the lead wire is fragile. Were you to bend the lead right at the body, the thinner part of this covering would fracture and the moisture seal would be compromised. Forming the lead before installing the part moves the stress point to the point of forming and retains the moisture resistance, and thus preserves the life expectancy of the component.
Have fun


