ALL VALVE RECEIVER poor sensitivity
Page 1 of 1
ALL VALVE RECEIVER poor sensitivity
Hi All,
I'm just after some advice on how to improve the sensitivity on my freshly built 'All Valve Receiver'. Despite being able to receive a hand full of foreign stations the receive sensitivity is only -65 dBm. The local oscillator and mixer input tank are 455 KHz apart and all the IFTs peak somewhere around where they should. The receiver input has a 50 ohm cable attached directly to the tap of the input tank (as per Harry's circuit) - no capacitor, back to a calibrated RF signal generator. Local oscillator input level to the mixer's grid is around 1-2v p-p. Test frequency 10 MHz. The IFTs used are from a Bush VHF.41 old valve radio. The IFT's internally are basic straightforward primary/secondary tanks with 110pf capacitors about 1/4-3/8' separation (hard to gauge).
Any advice would be appreciated!
Thanks,
ZL1TET Ed.
I'm just after some advice on how to improve the sensitivity on my freshly built 'All Valve Receiver'. Despite being able to receive a hand full of foreign stations the receive sensitivity is only -65 dBm. The local oscillator and mixer input tank are 455 KHz apart and all the IFTs peak somewhere around where they should. The receiver input has a 50 ohm cable attached directly to the tap of the input tank (as per Harry's circuit) - no capacitor, back to a calibrated RF signal generator. Local oscillator input level to the mixer's grid is around 1-2v p-p. Test frequency 10 MHz. The IFTs used are from a Bush VHF.41 old valve radio. The IFT's internally are basic straightforward primary/secondary tanks with 110pf capacitors about 1/4-3/8' separation (hard to gauge).
Any advice would be appreciated!
Thanks,
ZL1TET Ed.
zl1tet- Posts : 7
Join date : 2024-04-04
Similar topics
» All valve receiver modification
» ALL VALVE RECEIVER inductor former sizes
» Harry's Two-valve CW TX
» 2 valve transmitter
» Valve (tube) speaker transformer or smoothing choke idea
» ALL VALVE RECEIVER inductor former sizes
» Harry's Two-valve CW TX
» 2 valve transmitter
» Valve (tube) speaker transformer or smoothing choke idea
Page 1 of 1
Permissions in this forum:
You can reply to topics in this forum
|
|