That's correct! So if I were a tuner manufacturer I might be tempted to use an iron powder core for the balun rather than a "lossy" mix like #31 or #43 - the customer probably wont spot that it achie
Certainly Sevick's books are some of the very few available on the topic, but I'm not sure I would call them "definitive works". I know that may appear to be heresy, but I've now "invested" in 3 of S
If you wind a 4:1 Guanella balun as two identical 1:1 chokes on a common core, you force the CM voltages across the two chokes to be the same because they share the same flux. If we call the input vo
N6KB beat me to it! My schematics show nowhere the 4 supplies are connected together; but you do need a fifth, low current, supply to power the DC distribution board in the amplifier. In the 9420 the
The CorsairII has what appears to be a Bridge-Tee diplexer between the mixer and the Norton amplifier - R23, R24, L5, L6, C15, C16. However, the values of L5 and C16 look very odd. I don't know the v
That should have been: "....... you'd expect around 5.6uH to resonate with C15 at 9MHz" Steve G3TXQ I don't know the value of L6 (part# 21056), but you'd expect around 6.6uH to resonate with C15 at 9
Jerry, It's yet another error on the schematic! I lifted L5 this morning and measured it: 330nH, not 3.3mH; it resonates with C16 (1000pF) close to 9MHz. L9 and L10 on that same schematic are similar
Jerry, Both the L and the C in the diplexer parallel arm are fixed value; so low Q sounds good, given the tolerance issue :) However the L in the series arm of the diplexer is adjustable, and the boo
Simulating the TT diplexer I see just a couple of S11 excursions worse than -18dB (SWR=1.3:1), at 10MHz and 8MHz. Steve G3TXQ Both the L and the C in the diplexer parallel arm are fixed value; so low
Barry, I can't say for certain - I didn't lift them to measure! They are the same style of component as L5, and clearly the values can't be 8.2mH as shown. It seems likely the same sort of error has
A few calculations suggest that L9 and L10 *must* be 8.8uH, but I'll take a look and check the board. I agree that L11 and L12 must also be wrong - they obviously form some tuning/matching function.
I took another look at the CorsairII RF Mixer board (80987) inductors this morning: L1, L2, L3, L4, L7, L8: Green, radial body, marked 101. Measured as 100uH L5: Axial body marked Orange-Orange-Silve
One of the problems is that TT are not consistent in the way they label components. For example, on the 80987 board schematic all the RF blocking chokes are labelled 100mH; on all the other schematic
I finally decided I needed to do something about the "raspy" sidetone on my CorsairII. Being a lazy guy I was looking for a simple and easy modification that made a significant improvement with minim
Forgot to say: be sure to disconnect the radio from the PSU when doing the mod - you're very close to those mains terminals on the AF Gain/On-Off control. 73, Steve G3TXQ
That's correct - you need to choose your favourite sidetone frequency and pick the L&C appropriately. I don't see it as much of a limitation - I don't think I've altered my sidetone pitch in the 20+
@ Barry N1EU, Hope you don't mind me pointing out a small error in the "RF/IF Design" section of your Corsair II Wiki site. "Don't know about the Omni V and VI, but the "attenuator" switch on the Cor
Yes, I picked up 4 of them from RF Parts a couple of months ago. With them and a complete spare PA module I should be OK for a while :) Steve G3TXQ On 22/03/2013 14:07, Ralph wrote: Just a follow-up
I measured 12v p/p at the output of the low level amp on the Corsair II on 40m for 100W out of the radio. Into a 50 Ohm load that would equate to 360mW. Steve G3TXQ